Design Class Detail
PACO
PROJECT
Date
Expandability
Design
Item
Spare DCS I/O
Reducer Location
Design Class
Class 1
Class 2
No spare DCS I/O or
space for expansion
shall be provided.
Class 3
No spare DCS I/O shall be provided. Space for future
expansion shall be provided as defined by project.
TIC is 0.02% greater than Class 1.
Reducers shall be located outside globe valve
manifolds.
Reducers shall be located
outside globe valve
manifolds except on
applications where future
expansion is known.
TIC is 0.001% greater
than Class 1 per
application.
Capacity Utilization
Design
Item
Pump Fin/Fan
Control
Design Class
Class 1
Pump/Fin Fan control
shall be local only.
Class 2
Class 3
Select the appropriate:

Pumps/Fin Fans running continuously have local
Start/Stop and no Run indication

Pumps/Fin Fans that require start/stop more than
once a day require remote operation. Provide
remote run indications only when no other input that
would indicate operation is provided.

Pumps that require immediate action to start the
spare require auto-start

Pumps, valves and other equipment that are
manipulated by a batch or sequence control require
remote operation
TIC is 0.1% greater than Class 1.
Redundant
Control
Only one transmitter per
application.
One year or less pay-out
required for installation of
a redundant transmitter.
No UPS or back-up
power supply shall be
provided. (Potential Loss
of view once every 5
years)
UPS and back-up power supply shall be provided in
accordance with the EGGS.
Transmitters
UPS/Back-Up
Power
DEP 00.00.07.87-Gen.
Two year or less pay-out
required for installation of
a redundant transmitter.
TIC is 0.05% greater than Class 1.
Page 1 of 9
Design Class Detail
PACO
PROJECT
Date
Capacity Utilization (cont’d)
Design
Item
Freeze Protection
Process Analyzers
Design Class
Class 1
No freeze protection
shall be provided. Unit
will be shutdown and
drained for cold weather.
Only government
mandated process
analyzers (CEMS) will
be installed. Laboratory
analyzers will be used to
perform normal process
analysis.
Class 2
Class 3
Heat tracing and insulation shall be provided as required
by Location climate conditions.
TIC is 0.35% greater than Class 1.
Process analyzers will be
installed on streams that
require a continuous
analysis to monitor unit
operations. Analyzers with
continuous outputs may be
used for control of simple
loops in the DCS. These
loops require adequate
justification (one year
payout).
Analyzers may be used
for closed loop control
with the DCS and/or
computer system for
complex loops. Any
process analyzer/control
loop requires justification
to be installed on a
project.
Operability and Maintainability
Design
Item
Vendor Selection
DEP 00.00.07.87-Gen.
Design Class
Class 1
Consideration shall be
given to vendors not on
the SMFL, especially for
package systems.
Class 2
Class 3
Vendors shall be on the SMFL.
TIC is 0.05% greater than Class 1 per packaged unit.
Page 2 of 9
Design Class Detail
PACO
PROJECT
Date
Operability and Maintainability (cont’d)
Design
Item
Bypass Manifold
Around Control
Valves
Design Class
Class 1
No bypass valves
around control valves.
Class 2
Bypass manifolds shall be
used for the following
checked criteria.
 Primary feeds
 High maintenance
valves (e.g. cavitating
services, erosion)
 Loss of valve would
require a shutdown of
the unit.
 Reliability and resulting
cost/benefit shall be
addressed during review
of P&IDs.
Class 3
Most valves shall have
bypass manifold or
handwheel. Most control
valves shall be able to be
maintained with unit
remaining operational.
But, each control valve
application will be
determined during P&ID
review.
TIC is 0.56% greater than
Class 1 for carbon steel
and 0.7% greater than
Class 1 for stainless
steel.
TIC is 0.28% greater than
Class 1 for carbon steel
and 0.35% greater than
Class 1 for stainless steel.
Isolation of Control
Valves
Location of Control
Valves
Transmitter Manifold
Transmitter Support
DEP 00.00.07.87-Gen.
No block valves or
drains will be provided
for isolation of control
valves.
Block valves and drains will be provided for isolation of
control valves.
Control valves do not
have to be at grade or
accessible via platform
(i.e. may not be easily
accessible for
maintenance).
All control valves shall be at grade or a platform and
accessible for maintenance.
Transmitters do not have
to have manifolds (i.e.
root valve only) (May
need to shutdown to
replace instrument)
All transmitters shall have manifolds.
Transmitters may be
directly connected
(supported) on root
valve piping.
Transmitters shall be supported by cable or U-bolt to the
process line.
TIC is 0.74% greater than Class 1 for carbon steel block
valves and drains and 0.9% greater than Class 1 for
stainless steel block valves and drains.
TIC is 0.82% greater than Class 1.
TIC is 0.04% greater than Class 1.
TIC is 0.4% greater than Class 1.
Page 3 of 9
Design Class Detail
PACO
PROJECT
Date
Operability and Maintainability (cont’d)
Design
Item
Spare Instruments
Process Switch
Connection
Operational
Interlocks
Design Class
Class 1
Class 2
Class 3
No spare instruments
purchase. Rely on
vendor stock and current
plant spares. Exception
is known long lead items
such as remote
diaphragm seals.)
Normal spare parts justification and procurement.
Direct connected
process switches shall
be used in lieu of
transmitters (level,
pressure, flow,
temperature) and
receiver switch.
Transmitter with receiver switch shall be used for most
applications.
Use lowest cost
operational interlock
systems (DCS may be
the lowest cost option).
Use the DCS if it is the
lowest cost option.
Operational interlocks that
meet one of the following
criteria may be
implemented in the DCS as
well:
Class 2 + Implementation
of identified “vendor
package systems”
interlocks in the DCS.
Justification based on
reliability and
maintainability.
 Total loss greater than
$100M, less than
$500M.
TIC is 0.1% greater than
Class 1.
TIC is 0.2% greater than Class 1.
TIC is 0.02% greater than Class 1.
 Capital loss greater than
$50M, less than $100M.
 Demand rate greater
than one demand every
two years.
TIC is 0.06% greater than
Class 1.
Complex Loops
Standard Complex
Loops as defined by
16 GS-102 (e.g. ratio,
overrides, fanout)
Class 1 + Prototype complex loops installed to meet
project requirements. Class 3 plants may require more
prototype complex loops.
Continuous Process: TIC is 0.05% greater than
Class 1.
Batch Process: TIC is 0.10% TIC greater than
Class 1.
DEP 00.00.07.87-Gen.
Page 4 of 9
Design Class Detail
PACO
PROJECT
Date
Operability and Maintainability (cont’d)
Design
Item
Information System
Software
Design Class
Class 1
Class 2
Class 3
Points, NCF, groups,
trends, standard history,
keyboard layout.
Class 1 + two to three page
free format logs, operations
calculations. Update
existing LIMS and ODS
systems for identified
points.
Class 2 + custom history,
SPC, custom reports,
engineering calculations.
For each GUS: Nonnative graphics software.
TIC is 0.05% greater than
Class 1.
Information System
Hardware
TIC is 0.12% greater than
Class 1.
HM
AM, HM, VAX
AM, HM, VAX
2 GUS, single tier,
native windows
2-4 GUS total per operator.
The higher number of GUS
may be required for BATCH
or more complex units.
3-5 GUS total per
operator. The higher
number of GUS may be
required for BATCH or
more complex units.
Engineering Station.
TIC is 0.25% greater than
Class 1.
Engineering Station,
Remote View Station,
Supervisor Station,
New LIMS and ODS
facilities.
TIC is 0.36% greater than
Class 1.
Batch
No batch automation in
DCS
DCS configured for single
recipes, single mode of
operations.
TIC is 0.1% greater than
Class 1.
DCS customized:
recipes, lineups,
sequencers, abnormal
condition handlers, batch
logs, labelers, bar coders,
etc.
Special batch software
TIC is 0.3% greater than
Class 1.
DEP 00.00.07.87-Gen.
Page 5 of 9
Design Class Detail
PACO
PROJECT
Date
Operability and Maintainability (cont’d)
Design
Item
Custom Schematic
Displays
Design Class
Class 1
Class 2
Points that have outputs
are displayed once.
Identified process
overviews; Points that have
outputs may be shown on
multiple displays.
Full process overviews
and custom interfaces.
Digital points (not all) are
shown.
Approximately 75+
custom schematic
displays.
Approximately 30 to 40
custom schematic
displays
Approximately 40 to 75
custom schematic displays.
TIC is 0.05% greater than
Class 1.
Advanced Control
Controller Location
None
Direct connected or field
mounted controllers and
indicators shall be used.

DEP 00.00.07.87-Gen.
Class 3
All information points
shown.
TIC is 0.1% greater than
Class 1.
AM or VAX hardware.
AM or VAX hardware.
Advanced control
applications with six month
payout (batch is typically
less).
Advanced control
applications with one year
payout (batch is typically
less).
TIC is 0.15% greater than
Class 1.
TIC is 0.45% greater than
Class 1.
Most controllers shall be inside the control room
(individual controllers or DCS)
TIC is 0.18% greater than Class 1.
Unless the loops are
very simple and
small in number
(e.g. stand alone
unit; less than 15
loops) distributed
control system
(DCS) will be less
expensive. Also if
using DCS for
control room, DCS
loops are less
expensive than field
loops.
Page 6 of 9
Design Class Detail
PACO
PROJECT
Date
Operability and Maintainability (cont’d)
Design
Item
Pressure Regulators
Level Gauges/
Transmitters
PIs and TIs
DEP 00.00.07.87-Gen.
Design Class
Class 1
Pressure regulators shall
be used in the following
applications:

Air

Nitrogen

Water

Lube Oil

Steam

Tank Blanketing

Process with no
decontamination or
corrosion concerns
Class 2
Class 3
Pressure regulators shall only be used in accordance
with the DEPs.
TIC is 0.25% greater than Class 1.
If remote indication is
required, number of
level gauge glasses
shall be
eliminated/reduced. If
remote indication is not
required, only gauge
glasses shall be
provided.
All levels shall have gauge glasses with or without level
transmitter.
No local PIs or TIs shall
be provided. If justified,
thermowells and root
valves shall be provided
for devices to be
installed by Location as
needed. More local
indicators may be
needed since there is
limited information in
control room.
Local PIs and TIs shall be
installed by the project
except for the following:
 Local TIs for monitoring
exchanger
performance. Use TW
only or hand held
pyrometer.
 Local TIs where a TT is
provided
 Local PIs where a PT is
provided
TIC is 0.045% greater than
Class 1.
TIC is 0.093% greater than Class 1 for carbon steel.
TIC is 0.107% greater than Class 1 for stainless steel.
Local PIs and TIs shall be
installed by the project.
TIC is 0.09% greater than
Class 1.
Page 7 of 9
Design Class Detail
PACO
PROJECT
Date
Operability and Maintainability (cont’d)
Design
Item
Controllers/
Indicators
Design Class
Class 1
Class 2
Class 3
No indicators shall be
provided (i.e. controllers
only) in the control
room.
Controllers shall be
provided as required for
control. Indicators shall be
provided to monitor process
variables in a timely
manner. Do not provide
indicators to monitor
variables (such as
exchanger fouling or filter
delta pressures) which
change gradually over
weeks or months.
Indicators shall be
provided to monitor most
process variables.
TIC is 2.4% greater than
Class 1.
TIC is 1.6% greater than
Class 1.
Compressor Surge
Control System
Simple compressor
surge control system
shall be provided
(consider fixed point).
Compressor surge control
system shall be more
complex . System may be
in DCS as required by
machine and process.
TIC is 0.025% greater than
Class 1 for each
compressor if control is in
the TDC using a simple
algorithm.
Vibration Monitoring
Machinery shall have
probes and necessary
hardware for periodic
“manual” vibration
monitoring
Use of a special surge
controller (e.g. CCC with
measurements of suction
& discharge T,P,F)
should be justified basis
cost savings and risk of
damaging the
compressor.
TIC is 0.1% greater than
Class 1 for each
compressor.
Machinery shall have probes and necessary hardware
for continuous vibration monitoring at the local panel or
RIE/DCS.
TIC is 0.075% greater than Class 1 per compressor.
Operability and Maintainability (cont’d)
DEP 00.00.07.87-Gen.
Page 8 of 9
Design Class Detail
PACO
PROJECT
Design
Item
Date
Design Class
Class 1
Class 2
Class 3
No pump minimum flow
bypass or low flow
alarms shall be
provided. Operator shall
monitor the performance
of the equipment to
keep the pumps running
above their minimum
flow requirements.
Provide minimum flow
bypass for critical charge
pumps or other pumps
which would sustain
significant damage if flow
were stopped during normal
operation.
Pumping system in which
the flow through the
pump may be less than
minimum shall have
minimum flow bypass
This includes start-up,
normal, emergency, and
shutdown conditions.
No redundant HVAC for
control room or remote
instrument enclosure
(RIE) shall be provided.
Redundant HVAC shall be provided in control room and
RIE.
Protective
Instrument System
First choice for
protective instrument
system (PIS) shall be
relay; unless complex or
large number of
systems.
First choice for PIS is TMR microprocessor (Triconex).
Storage Tank
Instrumentation
Minimum or no
instrumentation shall be
provided.
Only local readout
instrumentation shall be
provided.
Instrumentation shall be
provided in accordance
with the EGGS.
Tank Gauging
Local level gauges
Honeywell smart
transmitters wired to
Honeywell HPMs.
Float-type transmitters
wired to dedicated tank
gauging systems.
If tank gauging system
exists, new float type
transmitters may be added
to it.
TIC is 0.10% greater than
Class 1.
Pump Minimum
Flow Bypass
Redundant HVAC
TIC is 0.1% greater than
Class 1.
TIC is 0.2% greater than
Class 1.
TIC is 0.08% greater than Class 1.
TIC is 0.075% greater than Class 1.
TIC is 0.05% greater than
Class 1.
DEP 00.00.07.87-Gen.
Page 9 of 9