SFC Key Interlocks & Process
Management Systems
Mechanical Control Systems
for Process, Pipeline & Plant
Maintenance Operations
Smith Flow Control Ltd
6 Waterside Business Park
Eastways Industrial Estate
Witham Essex CM8 3YQ
United Kingdom
Tel: +44 (0)1376 517901
Fax: +44 (0)1376 518720
sales@smithflowcontrol.com
www.smithflowcontrol.com
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03
Intro
06
QL Valve Interlock
08
GL Valve Interlock
10
Closures
12
Actuated Valves
14
Key Management Systems
16
ATL (Anti Tamper Lock)
18
Specials
22
Flexi-Drive
24
Easi-Drive
26
Pressure Protection
28
Pig Traps
30
Fire Deluge Systems
32
Fill In Sheets
‘...for over 20 years SFC have never failed to
provide a viable technical solution to a client’s
safety operating problem..’
Mike Smith - Founder & Vice-Chairman
Key Interlock Systems
Smith Flow Control (SFC) was established in 1985 to provide engineered safety solutions for
hazardous operations in the oil & gas and chemical processing industries.
SFC introduced the coded-card linear-key concept in a range of
modular key-operated interlocks to regulate operator execution
of work procedures on any form of host process equipment.
Typical applications include every form of valve (including
motorised and instrument valves), switches, vessel closures,
access guards, pressure and temperature sensing systems and
rail/road/sea tanker loading systems.
SFC's solutions in hazardous processes reduce the scope for
operator error and ensure safe continuous plant operation.
Most offshore installations in the North Sea have been
equipped with SFC systems as well as the majority of related
onshore processing facilities throughout Europe. By 1990 SFC
became the generic term for key interlock safety systems in the
international oil & gas industry and our client base now includes
most of the major operating companies in all five continents.
In 1990 SFC became part of Halma plc (quoted on the London
Stock Exchange) and in 1993 acquired ISO 9001 accreditation
certified by Lloyds Register.
Today SFC continues to be managed by its founders who remain
committed to providing quality assured products delivered on
time at a competitive price. SFC employs 50 people including 3
Design Engineers dedicated full time to product development
using 3D modelling, a full-time Quality Manager and 2 full-time
Works Quality Inspectors. Our manufacturing design office is
staffed by 8 Design Engineers who are all highly trained in the
capabilities of AutoCAD which is our chosen state-of-the-art
manufacturing design tool. SFC maintains a crew of 4 full time
fully certified Site Technicians which enable us to offer total
turn-key services to our clients.
OUR COMMITMENT
Smith Flow Control remain committed to providing quality assured products delivered on time at competitive prices.
This maxim was first stated when we formed our company in 1985 and remains the guiding principle for how we
conduct our business today.
We achieve these goals by relying on three core strands in our business culture - Innovation, Realisation and Dedication.
The SFC product range of valve interlocks have evolved over 20 years to provide highly reliable engineered process management
solutions to our clients. We achieve this by harnessing established mechanical principles applied to innovative design concepts
which are brought to realization using advanced CAD systems and exhaustive testing of pre-production prototypes.
The continuous quest for new product development and ongoing product improvement requires a level of energy and
commitment that can come only from a group marked by a collective dedication to being best in the industry.
We remain committed to retaining the confidence of our clients by staying true to the ideals that have gained us the reputation
we enjoy today.
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....."it would be difficult to name a
particular industry that would not
benefit from an SFC coded-card key
interlock system"
As a general principle it may be said that operations which are safe
when performed correctly can have catastrophic consequences when
performed incorrectly. The Oil & Gas and Chemical processing
industries generally have a disciplined approach to design and
operating practice - usually governed by well recognised international
standards and enforced by regulatory authorities and certification
bodies. While good practice begins with good design - both are
ultimately hostage to the ‘Human Factor ’.
Modern process plants are highly automated and regulated by distributed
software management systems which are simply monitored by 'Production'
personnel - often remote from the physical location of the plant itself.
Indeed, some operations such as pig launching or receiving procedures can
be effected in semi-automatic mode using push button controls (again often
from a remote station).
‘The obligation to adopt best
practice is a fundamental of safety
management - mechanical key
safety interlocking is a technology
that has evolved to offer
sophisticated technical solutions
to complex and hazardous process
applications and which
increasingly is being adopted by
major OpCo's worldwide for
protection of their people, their
assets and their surrounding
environment'
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Maintenance procedures however invariably involve human intervention and
interrupt automated processes creating 'abnormal' conditions for the duration
of the work. Loading or unloading of pig traps, changeover of pressure relief
valves, turbine servicing (requiring suspension of CO2 Fire Deluge), coupling or
uncoupling of hoses for loading or discharge of tanker cargoes all involve
human intervention and are hostage to the possibility of operator error.
Distributed control systems (DCS) cannot effectively regulate such
(maintenance) procedures - the SFC ‘Coded Card Key Interlock System’ can!
SFC 'Visual Alert' Key Cabinets
provide an effective and
infallible management control
system against unauthorised
or inadvertent operation of
interlocked valves or
associated process
equipment by keeping the
coded keys which initiate the
operation of critical valves
under secure supervisory
control.
BE SURE - BE SAFE - CHOOSE SFC - YOUR PARTNER FOR TOTAL PLANT SAFETY & SECURITY.
Controlling the sequence of events in which process
activities are conducted has been achieved historically
using Permit to Work (PtW) systems accompanied by
documented instructions.
However, this system is hostage to 'human
factors' Distractions, failure to interpret
correctly, ignorance of the system - all can
lead the operator to make errors which
can manifest themselves in
industrial accidents of varying
magnitudes.
Trapped Key Interlocks are
simple mechanical devices
which can be customised to
implement a safe sequence of
operation in any process activity.
In the following pages we show how our
mechanical key interlock system ensures that pig trap valves are
disabled and proven shut and the vessel is isolated, drained and
vented BEFORE opening of the closure for loading or unloading
of pigs, or, how the spare pressure safety relief valve is on
stream BEFORE an in-service relief valve can be isolated and
removed, or, how we prevent a tanker from
departing a loading/discharge station
BEFORE the cargo hoses are
disconnected.
These and any other work tasks
executed by human intervention
can be completely regulated by
SFC's coded-card key interlocks
- simple and total mechanical
reliability to prevent operator
error or violation to protect your
plant, the surrounding community and
the environment.
In addition to our range of high-integrity codedcard key interlock safety products, SFC also offer
a comprehensive range of valve and process equipment security
products for high and low-criticality applications.
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QL Valve Interlocks - For lever-operated valves
QLT
QLR
QL Valve Interlock (QLT & QLR)
QL valve (inter)locks suit all types of lever-o
operated quarter-tturn valves - including ball, butterfly, and plug valves.
Installing the (inter)lock on the host valve is a simple procedure as described below and requires no modification or hot-work to the
host equipment as the anchor and adaptors are custom-machined to suit the valve.
Adaptor
After removing the existing lever
the QL is assembled as follows:
Anchor
1. Install lock adaptor
2. Install anchor.
3. Fit SFC nut.
4. Assemble QL lock, secure
lever and tighten bolt.
Bolt
Lock
Body
SFC Nut
Lever
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Internal Mechanical Construction
QL Valve Interlock
Closed Key
Most offshore installations in the North Sea have been
equipped with SFC systems as well as the majority of
related onshore processing facilities throughout Europe.
Anti-Overide Mechanism
Product Features
316 Stainless steel construction
Closed Section
Linear ‘coded-ccard’ key design
Robust construction
Proven reliability in all climates
Locking Gear Cam
Single or double key versions
Open Key
Open Section
Anti-Tamper
Screw
Lock Body
SFC Nut
SFC Lever
Anchor
Lock Adaptor
For over 20 years SFC have never failed to provide a viable
technical solution to a client’s safety operating problem.
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GL Valve Interlocks - For handwheel-operated valves
GLS
GLM
GLM & GLS Valve Interlocks
GL valve (inter)locks suit all types of handwheel operated valves - including gate, globe, and
g e a r -o
operated valves.
Installing the (inter)lock on the host valve is a simple procedure as described below and requires no modification or hot-work to the
host equipment as the anchor and adaptors are custom machined items (Universal adaptors (UAS) may be supplied when precise
valve topworks data is not available).
After removing the existing
handwheel the GL is assembled
as follows:
SFC Nut
Lock
Body
Lock
Adaptor
Anchor
1. Mount lock adaptor and fix
SFC nut.
2. Locate body to adaptor.
3. Tighten fixing screws (x3).
4. Tighten setting screws to set
“Open” and “Closed” key free
positions.
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Internal Mechanical Construction
GL Valve Interlock
Mechanical Key Interlocks are robust maintenance-free
assemblies which provide reliable operational control of
safety-critical systems involving worker intervention. They
prevent accidents through operator error and greatly reduce
the scope for procedural violations and system abuse.
Locking Arm
Product Features
316 Stainless steel construction
Linear ‘coded-ccard’ key design
Counter Mechanism
Robust construction
Proven reliability in all climates
Single or double key versions
Key Release Arm
Code Bars
Lock Body
Anchor
SFC Nut
Lock Adaptor
For over 20 years SFC have never failed to provide a viable
technical solution to a client’s safety operating problem.
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Vessel Closures
Ensure total isolation,
venting and draining
BEFORE opening vessel
closure.
Introduction
Access into pressure vessels is a potentially hazardous
exercise. Residual pressure, volumes of residual liquids or
gases all can be harmful - typical examples of these potential
hazards include pig traps, slug catchers and filter housings.
Locking the vessel closure in the closed position ensures access into the
vessel can be achieved only under controlled safe conditions. The operating
key is held in a secure place - e.g. Control Room or Supervisor's office or is
retained (trapped) in some other related interlocked item of equipment.
As a minimum, vessel closures are usually interlocked with vessel venting
and draining functions - the interlocking arrangement can be extended to
incorporate all process items of equipment relating to the vessel's function.
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The SFC 'DL3' interlock is adaptable to all
types of vessel/access closures and is
very simple to use in pig trap applications
especially where the closure incorporates
a bleed device.
The 'DL3' interlock will be designed to
interface with the bleed function to
ensure the bleed screw cannot be
removed until the interlock permit key has
been inserted to unlock the 'DL3'
assembly.
When the 'DL3' is incorporated into vessel
access
safety
procedures,
total
equipment and personnel safety is
assured.
Prevent loss of containment of explosive or toxic product.
Any type of closure can
be fitted with the DL3
interlock, regardless of
their method of
operation. Design
details can be provided
on request.
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Actuated (Motorised) Valves
Actuated Valves
The most common requirement for key interlocking of poweractuated valves occurs in Pig Launcher/Receiver systems,
Scraper Traps and Sand Filter systems etc. where poweractuated valves need to be interlocked with manually-o
operated
valves and the vessel closure.
Because of the ultra-critical nature of such valves, special considerations
arise which the design of a key interlock system must address:Where such valves are part of an ESD system, the key interlock system must
not compromise the valve's fail-safe function.
Where pigging operations occur, the key interlock system must verify the
board
valve's absolute position (Open and/or Closed) independent of any on-b
instrument indication.
On electrical actuators where the key interlock system de-energises the
valve, any anti-condensation heating circuitry etc. must remain
uninterrupted.
Where actuators are equipped with a manual override facility, the key
interlock system must permit operation of the valve in both modes (or in a
combination of both modes - e.g. in the event of a power failure) while
maintaining the integrity of the key sequence at all times.
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Interlock system design principles
Because actuators generate great torque
forces, (b)locking of such valves by
mechanical restraint is unacceptable such locking methods would likely induce
damage within the motor assembly.
Nonetheless, a key interlock system must
ensure the valve is de-e
energised and
disabled (in both Remote and Local
modes) and that only the appropriate
sequence key is released for continuation
of the procedure dependent on the valve's
verified (Open or Closed) position.
A typical operating sequence is given on
the page opposite where it may be
observed the interlock system functions
‘passively’ and relies on the as-built
actuator mechanisms to establish and
confirm the status of the equipment.
It may also be observed when such valves
are in the ‘Open’ (‘Remote’ setting)
position - the valve is free to operate to
‘Closed’ without hindrance or interruption
by the interlock system.
Equipment Status:- Valve Open
Equipment Status:- Valve Closed
'SLU' Switch Unit Locked in 'REMOTE'.
'HWL' Handwheel Drive Locked 'OFF'.
'A' Key in Control Room.
'SLU' Switch Unit Locked 'OFF'.
'HWL' Handwheel Drive Locked 'OFF'.
'D' Key in Control Room.
To Close Valve:
To Open Valve:
1. 'A' Key into 'AKE' positional indicator unit.
'B' Key is removed from 'AKE' - 'A' Key trapped.
1. 'D' Key into 'AKE' positional indicator unit.
'C' Key is removed from 'AKE' - 'D' Key trapped.
2. 'B' Key into 'SLU' Switch Unit to unlock.
'SLU' Unit switched to 'LOCAL' ('B' & 'C' Keys trapped).
Operate button to close valve.
2. 'C' Key into 'SLU' Switch Unit to unlock.
'SLU' Unit switched to 'LOCAL'('B' & 'C' Keys trapped).
Operate button to open valve.
3. 'SLU' Unit now switched to 'OFF' - 'C' Key is removed.
'SLU' Unit locked in 'OFF' position trapping 'B' Key.
3. 'SLU' Unit now switched to 'REMOTE' - 'B' Key is removed.
'SLU' Unit locked in 'REMOTE' position trapping 'C' Key.
4. 'C' Key into' AKE' Unit - remove 'D' Key trapping 'C' Key.
'D' Key is then directed towards continuation of the procedure.
4. 'B' Key into 'AKE' Unit - remove 'A' Key trapping 'B' Key.
'A' Key is then directed towards continuation of the procedure.
NB The 'D' Key will not release unless the valve has completed
its full stroke to the CLOSED position.
NB The 'A' Key will not release unless the valve has completed its
full stroke to the OPEN position.
HWL
HWL
AKE Unit
AKE Unit
SLU Unit
SLU Unit
Hydraulic & Pneumatic Actuators
Power Failure Mode
A range of comparable designs are also available for springreturn and non-return hydraulic actuators and for spring-return
pneumatic actuators.
In the event of a power failure at anytime during either of the
above procedures, it is essential the integrity of the key
sequence is maintained if the valve is operated manually.
SFC's range of special process products also includes needle
valve locks, temperature and pressure sensing locks and a
range of signalling options to meet most process operating
requirements.
This is achieved simply by locking the 'SLU' Unit in the 'OFF'
position thereby releasing the 'C' Key. (Even if power is restored,
with the 'C' Key free, the valve/actuator will remain disabled).
The 'C' Key is inserted into the freewheeling 'HWL' handwheel
assembly - this lock functions on a 'declutching' principle. With
the 'C' Key trapped, the 'HWL' drive mechanism may be engaged
thereby enabling the valve to be operated.
While the 'C' Key can be removed from the 'HWL' assembly at any
time, it has to be exchanged through the 'AKE' unit to secure the
continuation key (i.e. the 'A' or 'D' Keys in the above examples)these keys will only release provided the valve has completed its
full stroke.
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Key Management Systems
SFC 'Visual Alert' and ‘Permit-tto-W
Work’ Key Management Systems
The SFC Key Interlock System has been developed through a
process of continuous design improvements acquired through
developing client safety management requirements over
twenty years.
Carbon or stainless steel construction.
‘Glazed’ door provides key status
without the need to open.
General to the system is the necessity for an effective and
efficient key management system that will provide a
continuous and reliable indication of the status of all
interlocked process systems.
Ingress protection from IP55 to IP66.
SFC 'Visual Alert' Key Cabinets provide an effective and infallible
management control system against unauthorised or inadvertent operation
of interlocked valves or associated process equipment by keeping the coded
keys which initiate the operation of critical valves under secure supervisory
control.
Total integrity by using dedicated
key locations.
The SFC 'Visual Alert' Key Management System dedicates and maintains the
operation of critical valve and process operations totally within the control of
the Designated Authority and the Performing Authority, enabling Permit to
Work (PtW) procedures to be carried out safely and efficiently. The system
concept is totally flexible and is designed in each case to integrate with each
client's operating system and working practices.
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Design features and benefits
Lockable doors.
External wall mounting brackets.
Complete key status awareness.
Key Cabinets
SFC Process Management Systems provide effective
protection to clients’ investments in plant and equipment
as well as improving employee safety and reducing the
risk of damage to the environment.
SFC Permit to Work (PtW) Systems
Having adopted a good key interlock control system,
the next most important step is to apply a good key
management system.
For storage, ease of access and issue, SFC key cabinets provide
all that is required.
A key cabinet should be located in a secure place; typically a
Control Room whereby initiating keys are issued by the Shift
Supervisor, Offshore Installation Manager (OIM) or other person
in authority.
Cabinets vary in size and can accommodate from 1 - 227 system
initiating (or spare) keys. Keys can be located via means of
hooks or holsters (the holster locator provides increased
capacity).
Each interlocked system has a dedicated engraved tag location
within the key cabinet. During periods of normal operations, all
interlock system 'permit' (initiating) keys are visually displayed
within the cabinet in dedicated locations.
Each key cabinet tag is engraved with the relevant piping
package data - this same data is also replicated on each system
key.
When the key is removed, a 'Visual Alert' tag is revealed
providing details of the key which has been issued, its
designated location, and the words 'WORK IN PROGRESS'.
Control Room staff have clear and easy indication of work status
at any time. Key cabinets can also accommodate mimic
diagrams. These are extracts of the P&ID diagram engraved onto
a Traffelite plaque and show clear details of all valves which are
interlocked.
Pin Coded System
SFC Key Cabinets can incorporate a Pin Code system which
prevents the replacing of a system key incorrectly.
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ATL (Anti-TTamper Lock)
Introduction
Many valves on site require a simple-to-use locking device to prevent
accidental or unauthorised operation.
Construction
ATL is available in two sizes covering all valve sizes and is available in 304
Stainless Steel. For remote unmonitored or higher security risk areas, a
carbon steel, case-hardened option is available, which will withstand the
toughest forms of vandalism.
Coding
The units can be uniquely coded or coded alike, dependant on operational
conditions/ requirements.
Operation
With the unit fitted to the valve, the standard SFC tamper-proof coded card
key can be inserted allowing valve operation.
Depending on operational requirements, the valve can be operated to any
position, once the key has been removed, the unit free wheels, preventing
valve operation.
Ordering
The units are available "off the shelf' allowing customers to undertake the
simple machining operation for fitting, thus reducing order times and
offering an instant security/safety solution.
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Many valves on site require a simple-ttouse locking device to prevent accidental
or unauthorised operation.
The ATL has been developed to fit directly
to valves in place of the normal
handwheel or operating lever, with little
machining which can easily be
undertaken by the customer.
Security Products
Where security lock-off devices are required to provide
mechanical locking of manual operators, SFC offer a full
complement of security and commissioning tools.
If sequential control is unnecessary but a secure lock is
required, the SFC range of security products can provide
the solution you need.
Chainlok
The Chainlok is a unique device which
combines the best features of
padlocks and interlocks.
Flag style 'Colour Aware Key' enables
incorporation into interlock (key
exchange) systems.
A durable body and chain made from
316 Stainless Steel makes it suitable
for use in the most hostile
environments. Chainlok comes with
O.5m chain as standard (longer
lengths available on request).
Flip caps prevent ingress of foreign
matter when key is removed.
ISO-LLOK
A multi-clasp, when used in
conjunction with SFC padlocks enable
individual personnel to isolate
equipment while they carry out their
work, safe in the knowledge that the
equipment cannot be re-energised
until all padlocks have been removed
from the clasp.
Car Seal
For 'one-time-only' securing of manual
operators, including securing of
manual valves, switches, enclosures. A
simple 'break-away' screw secures the
seal in place. Removal can only be
achieved by cutting the seal cable.
Two body and cable sizes are available,
along with varying lengths of cable.
Cable breaking strains are available to
1750kg.
Re-usable car seals are also available.
Ideal for use in commissioning procedures
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Specials
Specials
The range of process applications to which
SFC interlocks can be applied is unlimited. As
clients begin to understand the immense
operational capabilities of SFC interlock
systems, they often request unique solutions
to specific problems.
In this section we present some examples of
'specials' we have developed to meet clients'
specific operating safety requirements.
SFC are always pleased to receive a
challenge to provide unique solutions to
clients' individual or special problems.
Pressure Protection - using 3-w
way changeover valves.
Customer Problem:
To remove dependence on chain-drive
mechanisms on mechanically-linked 3way changeover valves located upstream
and downstream of dual safety relief
valves.
The client's anxiety arose through concern
for the possible consequences of an
overpressure situation arising in the event
of a failure in the chain drive mechanism
during a relief valve changeover
procedure.
SFC Solution:
SFC's solution enabled removal of the
chain drive mechanism and relied on a
locking arrangement that first established
an intermediate (mid point) safe position
on the downstream 3-way valve assembly.
This permitted the release of a transfer
key that then enabled a full changeover
on the upstream 3-way valve assembly
before releasing a final key to complete
the downstream procedure.
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3-W
Way Isolating Valve C/W Proximity Sensor
Customer Problem:
To interlock a single acting, pneumatic
actuator on a ball valve.
SFC Solution:
Where
single-acting,
spring-return
pneumatically actuated valves have to be
incorporated into an interlock sequence,
an interlocked 3-way isolating valve is a
simple and effective solution.
The isolating valve is located upstream of
the actuator control panel. When
operating the isolating valve, air pressure
to the actuator is vented to atmosphere,
thus completely disabling the valve which
will then operate automatically to it’s
designed fail-safe position.
Single or double key arrangements can be
used to isolate the valve in any position.
In the illustration the interlock
incorporates a chassis plate for local wall
mounting, and a proximity sensor for
status indication back to a control room.
This arrangement is a cost effective addon control feature to all types of
pneumatic, hydraulic or gas actuators.
Modular Double Block & Bleed Valve
Customer Problem:
Restrictions of space require that a
modular style double block and bleed
valve is used in place of a conventional 3
valve piped arrangement. It is required
that the modular valve is interlocked with
other valves in the system.
SFC Solution:
Modular valves of this type pose greater
problems for interlocking by virtue of their
size and space limitations. SFC designed
a bespoke cam type interlock especially
for this host valve.
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Specials
Needle Valve Locks
Customer Problem:
To ensure two ports on an instrument
manifold can never be simultaneously
opened.
SFC Solution:
Needle valves of all types can be fitted
with SFC interlocks. Regardless of body
design, number of operating handles or
method of operation, SFC can supply a
solution to your problem.
In this illustration a 4-port instrument
manifold is equipped with SFC's NVL
interlock. The locking device ensures that
pairs of operating handles can only be
operated one at a time.
Upon opening the first port, the key
becomes trapped. The second port
cannot be opened until such time that the
first port has been closed, thus releasing
the operating key.
The opposite pair of ports are controlled in
the same way with a differently coded key.
Explosion Proof Interlocked Switch
Customer Problem:
To mechanically interlock an electrically
operated device, within a hazardous
environment - ATEX certified.
SFC Solution:
Where mechanical (interlocked) control of
powered equipment is required in a
hazardous area, the SFC switch lock
provides the perfect solution.
In this illustration our 'QL' quarter turn
interlock is fitted to the switch mechanism
of an II 2 G D hazardous area control
switch.
A single or dual key configuration can be
supplied to lock in the 'ON', 'OFF' or both
positions.
Switches for hazardous zone protection
specifications can be provided including
solenoid controlled key release units.
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Sequence Control Unit
Customer Problem:
To permit complex variations in operating
sequences on launcher/receiver systems.
SFC Solution:
The simplest interlock systems will
normally feature a 'linear sequence'. This
is where the outward 'journey' (operating
steps) are mirrored by the return journey.
However, from time to time non-linear
sequences are necessary. A typical
example of a non-linear sequence is a pig
receiving procedure where double block
and bleed valves control complex nitrogen
purging, pressure equalisation, venting
and draining.
The sequence control unit is a mechanical
key issuing/control device. It is normally
placed locally to the valve system. It
differs from a key exchange unit in that,
upon inserting a permit key, a selector
knob is rotated to a fixed position before
the next key is issued.
Pneumatic Control Valves
Customer Problem:
To interlock a double acting, pneumatic
actuator on a ball valve.
SFC Solution:
For this requirement SFC adapted their
QLA interlock to incorporate a sliding
control lever with forward and backwards
motion.
This linear motion interfaced with the
pneumatic valve operating lever to provide
double acting operation.
21
Flexi-D
Drive
Flexi-D
Drive
Flexi-Drive is a very versatile product consisting of two stations, joined by a
unique patented linear drive cable.
This equipment enables valves and other wheel-operated devices in remote,
hard-to-reach or hazardous locations to be operated easily from a
conveniently located and safe handwheel station.
Developed originally for use by the US Navy to operate valves in inaccessible
locations on board ships, Flexi-Drive can now be applied to any conventional
wheel-operated valve/device, in oil, gas and chemical processing plants. It is
suitable for underwater applications and will function reliably in all climatic
conditions.
The cable system can transmit drive to a valve up to 60 metres from the
operator station. The flexible cable system facilitates up to 540° of bends in
the cable run.
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What Industry?
Practically any industry where valves are
used would benefit from the Flexi-Drive
System. SFC can design and install FlexiDrive to meet strict safety guidelines and
regulatory body requirements.
Additional details of all products
illustrated are available on our web site at
www.smithflowcontrol.com
Remote Cable Drive Valve Operators
In a hazardous area, below water, in a confined
space, in a pit, where noxious fugitive emissions
prevail or where valves are just plain out of
reach, Flexi-Drive is the answer.
Operation
2
1
1 Operator Station Actuator
Input torque at the operator station turns a pinion
shaft that drives a cable gear. Operator stations
are available in a variety of gear ratios, providing
a wide range of torque capabilities. A helically
wound steel cable has a pitch the same as that of
the cable gear. This precision gear-cable interface
provides a positive force to the helix cable, which
travels through the flexible conduit to the valve
station actuator.
2 Valve Station Actuator
The valve station serves as the torque-producing
component located at the valve end of the
system. Linear motion of the steel helix cable is
converted back into a rotary motion at the valve
station for valve operation.
RVO Systems
The cable system can be passed around and through walls, bulkheads, floors
and any other obstacles to reach the valve.
SFC Flexi-Drive Remote Valve Operator (RVO)
systems comprise of four basic elements:
Operator Station Actuator
Helical Drive Cable
Valve Station Actuator
Valve Drive Coupling
(designed to suit the host equipment)
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Easi-D
Drive
Typical gearoperated gate
valve,
pneumatically
driven using a
'universal', bolt-on
handwheel drive
plate and reaction
device.
Easi-D
Drive
Low cost alternative to permanent dedicated actuators.
No requirement for dedicated power supply.
Operates from adjacent plant air or single-phase electrical supply.
Suitable for use in all Hazardous Areas.
Ideal for minimum facilities installations.
Suitable for all climatic conditions.
Wide band torque capability with variable torque adjustment as standard.
Ideal for moving tight or partially-seized valves.
Adaptable to any size/type of valve.
Eliminates operator fatigue and greatly reduces the risk of injury.
Reduces work crew tasks to one-man operation.
Fully portable - can manage banks of valves with a single drive tool.
Three simple steps to easi-d
drive
installation and use:
1 Decide if you want to retain
the option of manual valve
operation via the handwheel.
2 Install the relevant easi-drive
equipment.
3 Connect drive gun to power
supply (pneumatic, electric or
hydraulic).
24
Typical gear-operated ball
valve, pneumatically driven
using a universal ‘bolt-on’
handwheel drive plate and
bespoke (custom made)
reaction device.
Standard equipment and basic
specifications:
Pneumatic, electric and hydraulic 'drive
guns' available.
‘Local’ pistol grip type tools available.
Barrel type tools.
Customised valve drive adaptors.
Standard hose length supplied: 3 meters.
Air supply recommendations: 840 I/m
(30cfm) @ 5.5 bar (80psi).
Guns available with a range of torque
outputs: 100 Nm (74 Ibf ft) to 100,000
Nm (73, 700 Ibf ft).
Torque safety cut out facility.
Continuous run and 'dead mans handle'
options.
Calibration certificates supplied.
Portable Valve Actuators
Pneumatic Tool
Easi-Drive is an efficient and cost-effective alternative to a
dedicated actuator. Wherever you have manually-operated
valves that have high operating torques, hundreds of handwheel
turns to open/close or are just difficult to operate then EasiDrive is your solution.
Product Features
Each drive tool has a unique serial number and is supplied with
it’s corresponding certificate of calibration.
The example provided shows the relationship between the input
air supply pressure, via the SFC air filter, regulator and lubro
(FRL) pack and the output torque that the drive tool can
produce.
By adjusting the air pressure you can easily restrict the torque
output of the drive tool for your precise requirements.
Certicate of Calibration
Options
Electrical
Battery
Operated
Hydraulic
Smith Flow Control can also supply an electrical
version of the Easi-D
Drive with features including:
Pistol grip.
Range of voltages.
Customised valve drive adaptors
Switchable maximum torque level feature
LCD display indicates direction of drive and
current maximum torque
Output +1- feature buttons to adjust torque
CE and EMC certified
Calibration certificate
Also available is a range of hydraulic Easi-D
Drive
operators, features include:
Powerful continuous rotation.
Air and electric powered hydraulic pumps available.
Can be used subsea via umbilicals and ROV's.
Customised valve drive adaptors.
Calibration certificate.
25
Pressure Protection
Pressure Protection
Whether onshore or offshore, maintenance procedures to Safety Relief
Systems on live plant cause concern in ensuring that an open path to relief
is maintained at all times during the work exercise.
Most modern piping arrangements include spare relief capacity enabling
continuous production while such maintenance procedures are conducted
on live plant eliminating the requirement to isolate and shut down the
process.
Twin or multiple safety relief valve systems are usually fitted with isolation
block valves upstream and downstream of each safety relief valve - it is
essential to ensure that the block valves isolating the spare relief valve are
opened BEFORE the block valves of the workpiece relief valve are closed.
This issue is a more acute problem if the respective relief valves and isolating
block valves are distant or out of sight of each other.
Various API and ASME codes recognise this hazard and recommend the use
of interlocks to eliminate this possibility. API RP 520 (Pressure Relieving
Systems for Refinery Services - Part II Section 4- Isolation Valve
Requirements) and API RP 14E (Design and Installation of Offshore
Production Platform Piping Systems - Para 5.8b [2] - Relief Device Piping)
specifically recommend interlocks in this situation to ensure that
(over)pressure protection of the vessel is not compromised. These
recommendations are also in accordance with the requirements of ASME Section VIII - Appendix M.
Fitting a valve interlock to the upstream and downstream isolating valves on
each safety relief valve (PSV) will ensure these recommendations are
implemented.
An initiating key, issued from a secure location (Control Room) commences
the PSV changeover. Follow the step-by-step procedures in the diagram.
26
....... 'apart from the possibility of death or injury to
personnel, or pollution of the locality, what other possible
impact could an over-pressure explosion or rupture of one
of your main process vessels have on your business' ?
Typical ‘4 Block Valve / 5 Key’ Interlock System
PSV 1
PSV 2
V1 - Keys A & B
V4 - Keys E & D
V2 - Keys B & C
V3 - Keys C & D
ILLUSTRATION STATUS:
PSV1 on line: PSV2 isolated
Block Valves V1, V2 & V4* are Locked Open (LO.)
Block Valve V3 is Locked Closed (LC)
*Spare outlet (downstream) block valve normally LO especially if
lower pressure rated than corresponding inlet (upstream) block
valve
Requirement:
There is always an open path to relief.
(Inlet block valves V2 & V3 must never be closed at the same
time)
Maintenance Task:
To commission PSV2 into service.
To isolate and permit removal of PSV1 for testing/servicing.
Work Sequence:
1. Key 'D' is issued from the Control Room to initiate the Permit
to Work
2. Key 'D' unlocks and enables the opening of spare inlet block
valve V3
3. V3 is operated to open and is LO by removing Key 'C' - PSV2 is
now on line.
4. Key 'C' is transferred to unlock and close inlet block valve V2
5. V2 is LC by removing Key 'B'
6. Key 'B' is transferred to unlock and close outlet block valve V1
7. V1 is LC by removing Key 'A'
The return of Key 'A' to the Control Room closes-out the work
permit and enables the issue of instructions for removal of PSV1
for testing and servicing.
Twin PSV Changeover Sequence
It should be noted this interlock arrangement further ensures
that the higher pressure rated inlet block valve V2 is closed
before its corresponding lower pressure rated outlet block valve
(V1). Conversely, this key interlock arrangement would also
ensure opening of low pressure outlet block valves before
opening of high pressure inlet block valves.
27
Pig Traps
Pig Traps
Pig trap accidents involving operator intervention can be
prevented by SFC coded-ccard key interlock systems.
DNV TN B 302 Technical Notes for Fixed Offshore Installations describes pig
traps as 'primary grades sources of hazard'. ASME and API codes equally
recognise pig trap hazards - especially in relation to the risk of opening
closures while the vessel remains under pressure. The Pipelines Safety
Regulations 1996 enacted into UK law in April 1996 requires operators of
pipelines to provide safety systems that ensure persons are protected from
risk to their health and safety - again describing the hazard of opening pig
trap vessels under pressure.
SFC interlocks can be specified to ensure the minimum safety
arrangement of interlocking the vessel vent valve with the pig trap
closure. This arrangement ensures (to the exclusion of all other
methods) the vessel VENT valve is OPEN before any attempt can be
made to open the closure.
With interlocks fitted to both the vent valve and pig trap closure, a key is
released when the vent valve is opened - removing the key from the vent
valve locks the valve in the open position This key is coded in common with
the closure lock - only by opening and locking the vent valve can the operator
secure the correct key to proceed to unlock and open the closure.
28
Mechanical Principles
(Bleed devices fitted into closure opening
mechanisms are alone an unreliable
safety arrangement to detect the
presence of residual product. They are
prone to wax or hydrates formations
which can obstruct the bleed channel
inside the vessel thereby misleading the
operator to believe It Is safe to open the
closure}.
Safe Loading and Unloading of Pig Traps
....."Imagine the consequences of opening a pig trap
closure with product in the barrel"
....."Imagine the effect of attempting to pass a pig through
a partially open outlet valve"
....."Imagine getting a sniff of H2S "
.....tthese things can happen - have happened!
Pig Traps
Further procedure sequences can be regulated by interlocks to
include drain valves, nitrogen purge and water flush valves,
corrosion inhibitor and isotope functions, and indeed main
inlet/outlet and kicker valve functions - every system is designed
to meet clients' unique operating conditions/requirements.
Key interlocks can be integrated
into pig trap control systems even
where the main inlet/outlet valves
and kicker valve are actuated
(MOV's). In this situation,
launching or receiving pigs is a
semi-automatic process with
operator intervention limited to
push-button action either through
a local control panel or effected
from a remote control station.
Indeed, these valves may even be
programmed with ESD functions.
However, when it comes to loading
or unloading of pigs, an abnormal
condition arises where software
or electronic interlocking arrangements between these valves
are suspended through the necessity to isolate these valves
both from 'Remote' and 'Local' settings to the 'Off' position. An
SFC coded-card key interlock system can be fitted to these
valves to mechanically prove their 'closed and isolated' status releasing a key which then enables
operation of manually-operated
valves related to vent, drain, N2
purge and water flush procedures
before enabling any attempt to
unlock and open the pig trap
closure.
Only an SFC coded-card key
interlock system can achieve the
condition of creating a positive link
that makes the operation/status of
MOV's and manually-operated
valves completely interdependent
and absolutely reliably ensures
total isolation, venting and draining
of the vessel BEFORE any attempt
can be made to open the vessel
closure!
Mechanical Key Safety
Mechanical key safety interlocking is the ONLY technology that can assure the universally accepted requirement in the loading
and unloading of pig traps that the vessel is venting BEFORE it is possible to open the vessel closure. A key is released when
the vent valve is unlocked and opened which then enables unlocking of the closure mechanism. This imperative is defined
variously in the following standards and regulations:ASME VIII - Division 1
1996 No. 825 - (UK) Pipeline Safety Regulations (Section 6 - Para. 37 of Guidance on Regulations - UK Health & Safety
Executive).
US DoT - Pipeline Safety Regulations - Part 195 Transportation of Hazardous Liquids by Pipeline (§195.426 Scraper & Sphere
Facilities).
Shell DEP 31.40.10.13 - Gen : Design of Pipeline Pig Trap Systems.
29
CO2 Fire Deluge Systems
Fire Deluge Systems
International concern over the environmental effect of widespread use of
CFC gases has led to the phasing out of HALON (Halon 1301) as a fire
extinguishing medium and its substitution with Carbon Dioxide (CO2) or other
inert gases.
Mechanical Principles
CO2 is a very effective extinguishing agent and works by reducing oxygen
levels to a point where combustion cannot be sustained. It is a naturally
occurring substance and has no corrupting or polluting effect when released
into the atmosphere - unlike HALON which is a CFC compound.
Automatic CO2 fire extinguishing systems when activated are designed to
deluge an area within seconds. Typical installations include
turbine/generator enclosures, plenum chambers, computer rooms, archives
or any other enclosed area designated as being not-normally-occupied. Such
areas are occupied only on an occasional basis usually for the purposes of
inspection, maintenance or repair.
30
CO2 is potentially fatal - anyone who may
become trapped in an enclosed space
flooded with CO 2 would very quickly
suffocate.
.......'what's colourless, odourless, is all around us and
can kill a person in less than 2 minutes' ? .......
Safe Practice
Safe practice requires an arrangement which prevents casual or
unauthorised access into a (CO2) protected space and also
enables emergency exit at all times from the protected area. The
safety arrangements should also ensure that all doors and
access hatches remain locked during periods of normal
operations and that access to the protected area is controlled
and authorised only by the appointed authority.
key(s) which enable isolation of the CO2 supply. Based on a key
exchange principle, further keys are released which enable
unlocking of the access door(s) and permit the entry of the
worker(s) to undertake the task at hand.
SFC interlock systems can be applied for maximum effect to
permit access only under the strictest conditions. Access for
inspection or maintenance purposes is only possible by the
issue of an initiating 'permit key' by the appointed authority. This
key may be used to activate visual or audible alarms which
denote 'work in progress' and / or the release of secondary
* National Fire Protection Association (USA) - Carbon Dioxide
Extinguishing Systems - 1993 Edition
This safety solution from SFC fulfills the safety requirements of
NFPA12 * and BS 5306. #
# British Standard - Part 41986 - Specification for Carbon
Dioxide Systems
For the period in which work
is being carried out inside
the enclosed space, the
CO2 Supply is isolated and
the worker(s} cannot be
locked in. However, to
ensure total worker safety
each interlocked access
door within the system is
fitted with a failsafe
emergency override escape
mechanism which permits a
worker to strike a panic
button or crash rail that
mechanically overrides the
door latch mechanism.
31
Gate Valve Fill In Sheet (Specimen only)
Main Dimensions
Handwheel Drive Form
AA = ..............
CC = ..............
W = .................
Y = ................
BB =...............
DD =.................
X =.................
Z = ................
Valve Orientation
Easi-D
Drive Universal Handwheel Drive Plate
A= .......
A= .........
B =. . . . . . . . .
C= .......
F =. . . . . . . . .
G=.........
I=........
J= .........
K= . . . . . . . . .
L= .........
M= ........
N= .........
Q =. . . . . . . . .
P= .........
S =. . . . . . . . .
R= .........
U =. . . . . . . . .
X= .........
W= ........
AA = . . . . . . . .
Z =. . . . . . . . .
CC = . . . . . . .
BB =. . . . . . . .
LL = . . . . . . . .
Size. . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Rating . . . . . . . . . . . . . . . .
Make. . . . . . . . . . . . . . . . . . . . . . . . .
32
EE = ..............
GG = ..............
JJ = ..............
FF=................
HH =...............
KK =.............
Preferred Power Supply
1. Pneumatic
2. Electric
3. Hydraulic
Site supply?
Pneumatic air supply pressure psi/bar?
Electrical Supply Rating
1. Rating
Hydraulic Supply Pressure
1. psi/bar
Valve Information
1. Breakout torque
2. Run torque
3. Reseat torque
LL = ..............
Gearbox Fill In Sheet (Specimen only)
Main Dimensions
Orientation
Handwheel Stem Form
X= .........
Y= .........
Z= .........
AA = . . . . . . . .
A1 = . . . . . . . .
B1 = . . . . . .
KW = . . . . . . .
A= .........
M= ........
B= .......
M1 = . . . . . . .
C= .........
M2 = . . . . . . .
D= .........
M3 = . . . . . . .
E= .......
N= .........
F= .........
P= .........
G=.........
H= .........
Or
PCD
Q=.........
R= .........
I= ........
S= .........
J= .........
‘T’ = . . . . . . . .
J1 = . . . . . . . .
‘T1’ = . . . . . . .
K= .........
‘T2’ = . . . . . . .
L= .........
U= .........
(V) = . . . . . . . .
Size. . . . . . . . . . . . . . . . . .
Easi-D
Drive Universal Handwheel Drive Plate
W= ........
EE = ..............
HH = ..............
KK = ............
GG=................
JJ =...............
LL =..............
Pressure Rating . . . . . . . .
Make. . . . . . . . . . . . . . . . .
33
Ball Valve Fill In Sheet (Specimen only)
Main Dimensions
Typical Other Form Types
AA = ..............
BB = ..............
CC = ..............
DD = ..............
Note: Please note that this fill-in sheet is
for example purposes only.
Please contact our technical sales team,
should your valve differ significantly from
the illustration shown.
A= .........
H= .........
B= .........
I= .........
C= .........
J= .........
D= .........
K= .........
E= .........
L=........
F= .........
M= ........
G=.........
N= .......
O=.........
Size . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure Rating . . . . . . . . . . . . . . . . . . . . . . . . .
Lever Length . . . . . . . . . . . . . . . . . . . . . . . . . . .
Make . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
34
SFC....Global market interests
We supply and support some of the worlds biggest companies involved in the oil
& gas and petro-chemical industries. Since our formation in 1985 we have
partnered most of the world’s leading oil & gas producers and chemical
processors by developing and delivering innovative engineering solutions to
manage and protect their multi-billion dollar field asset investments.
Our clients rely on our engineering expertise and product reliability to assure
standards of operating safety demanded in modern society. We remain focused
on the continuous task of meeting and exceeding those demands.
As part of a process of on-going product development, Smith Flow Control reserves
the right to amend and change specifications without prior notice.
Published data may be subject to change.
For the very latest version release, visit our website at www.smithflowcontrol.com
35
SFC Key Interlocks
& Process Management Systems
6 Waterside Business Park
Eastways Industrial Estate
Witham Essex CM8 3YQ
United Kingdom
Tel: +44 (0)1376 517901
Fax: +44 (0)1376 518720
sales@smithflowcontrol.com
www.smithflowcontrol.com
Edition Date 04/2006