Title: Pressure Relief Device In-Line Isolation Device Control Procedure
Site
Procedure
Function: Safety
No.: MC032.020
McIntosh Site
Preparer: B. Lax
Effective
EHS Specialist
11/2015
Owner: M. Ware
EHS Team Leader
Page: 1 of 4
Supersedes:
11/2012
Approver: G. Vann
Site Manager
1.
PURPOSE
The procedure details the administrative requirements for safely using in-line isolation
devices with pressure relief devices.
2.
DEFINITIONS
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3.
High Quality Administrative Program – an administrative program designed to
manage a system that is deemed to have high failure consequences. It should be
used only when no engineering control is available to manage the risk. Typical
systems utilize multiple levels of the organization with the 4-eyes principle, checklist,
sign-offs as well as audit and certification processes.
In-line Isolation Device – a valve or spectacle blind installed in-line with a pressure
relief device which can be closed while a pressure relief devices is in service thus
preventing the pressure relief device from protecting the subject equipment. Three
way valves used for tandem pressure relief device installations are NOT considered to
be in-line isolation devices if one outlet is always open. They will be addressed in a
section below and managed at a unit level.
Pressure Relief Device (PRD) – a mechanical device used to prevent over pressure
of equipment. Common devices include pressure relief valves, rupture disks,
conservation vents or vapor vacuum vents. In this document, they will be referred to
as PRDs.
SCOPE
This policy covers all operating areas of the McIntosh site that isolate PRDs from the
equipment they are intended to protect.
4.
PROCEDURE
4.1.
Creation and Maintenance of Site List of PRDs with In-line Isolation Devices
4.1.1. Blockage of inlets or outlets of PRDs can result in catastrophic
consequences. PRDs are, in most cases, the primary safety device for a
piece of equipment. For these reasons, the installation of an in-line isolation
device that can block a PRD must be made only as a last resort. The control
of those devices shall be handled using this procedure, which constitutes a
High Quality Administrative Program. A list of all PRDs with in-line isolation
devices shall be made for the McIntosh site. All PRDs, whether in a
PSM/RMP covered process or a non-covered process, shall be included.
The list shall contain the unit or operations area name, PRD identification
number, P&ID number, protected equipment number and reason for
installation as well as the normal position of the device ( in most cases
locked open). An electronic copy of this list shall be maintained by the EHS
BASF Corporation
McIntosh
Procedure
Title: Pressure Relief Device In-Line Isolation Device Control Procedure
Function: Safety
No.: MC032.020
Page: 2 of 4
Effective:
11/2015
Supersedes:
11/2012
records coordinator. The list is included with the procedure as Attachment
A.
4.1.2. Any additions or deletions to the list shall be made prior to the device being
placed in service or upon removal as a matter of closure of the MOC PSSR
for the change. To modify the site list, a request with the required
information shall be sent to the EHS records coordinator and the EHS Group
Leader.
4.2.
Identification and Locking of In-line Isolation Devices
4.2.1. Each isolation device included in the site list will be locked with a production
lock. This will not be the same lock used for LOTO. Also, a Safety Critical
Caution will be attached to the lock. The following will be printed
legibly on the tag: “Lock removal bypasses a critical safety
function. Lock removal is prohibited unless a SWP is completed
per site policy MC032.020..” The instrument / equipment number of the
affected PRD shall be noted on the tag as well.
4.3.
Semi-Annual Unit Audits of In-line Isolation Devices and Annual Certification of Unit
List
4.3.1. On a semi-annual basis, a visual inspection of the in-line isolation devices on
PRDs for each unit will be conducted by a production supervisor. A check
list will be completed and returned to the unit manager for review. This
check list shall document that the device is locked in the proper position, that
the lock is not degraded, and that the tagging is legible. Any discrepancies
shall be repaired immediately and so noted on the check list. This task will
be scheduled in the regulatory tracking system and completion will be noted
there as well.
4.3.2. On an annual basis, the unit manager shall review the previous semi-annual
audit checklists, described in section 4.3.1, and certify that the unit list
created per section 4.1 is still valid and that all devices are in the proper
position. The annual certification will be scheduled in the regulatory tracking
system to be completed by January 31 of each year. The annual
certification shall not replace the obligation of the production unit to keep the
list current during the year if changes occur.
4.4.
Changing Normal Operating Positions of In-line Isolation Devices and Return to
Normal Service.
4.4.1. For the purpose of maintenance, it may be necessary to change the locked
position of an in-line isolation device on a PRD. This situation shall be
governed by a Safe Work Permit approved by the owning department
operations manager or their designee.
BASF Corporation
McIntosh
Procedure
Title: Pressure Relief Device In-Line Isolation Device Control Procedure
Function: Safety
No.: MC032.020
Page: 3 of 4
Effective:
11/2015
Supersedes:
11/2012
4.4.2. The Safe Work Permit shall detail how the unit will assure that all energy
sources are isolated from the equipment to prevent a potential over pressure
and that liquid-full systems are cleared, if possible, while work is being
performed. The Safe Work Permit will also discuss how the system will be
returned to normal service.
4.4.3. After all energy isolation has occurred and the task to be performed has a
valid SWP with LOTO, the lock and tag described in section 4.2 on the inline isolation device shall be removed by the owning department supervisor.
The SWP shall be issued by the owning department operations manager or
their designee thus increasing the level of oversight above normal SWPs.
The fact that this SWP and LOTO are being conducted on a safety critical
system shall be clearly explained to all parties involved in the permit.
4.4.4. At the completion of the work on the PRD, and as part of returning the
system to normal operations, the owning department supervisor will place
the in-line isolation device in the correct operational position per the site list.
The owning department supervisor will also lock and tag the valve per
section 4.2 of this procedure. This will be done prior to any other lock being
removed from the LOTO of the system to ensure that the system will be
protected prior to any energy being introduced the system. The SWP and
LOTO will be part of the record related to managing the safe operation of the
PRD. The completed permits shall be returned to the unit manager.
4.4.5. The completed SWP and LOTO shall be maintained with the audit checklists
as a record to verify that the device has been correctly returned to service.
4.5.
Use of 3 Way Valves In-line with PRDs
4.5.1. In many cases, the production units have opted to use three way valves
where two PRDs are installed on the outlets of these valves. As long as the
unit can ensure that one leg of the 3 way valve is open at all times, this
procedure does not apply. It is required that the production units document
this information along with the location of the valves. A record of this shall
be maintained by the operations manager. Due to the hazards involved with
removing a PRD from a 3 way valve, it is required that a Job Hazard
Analysis be completed prior to removal of the relief device. The JHA must
focus on the proper use of the 3 way valve as well as ensure the safe
removal of the PRDs. The JHA should become a part of the job package for
that PRD PM program.
4.6.
Best Practices for New Installations and Non Mandatory Retrofits to In-line Isolation
Devices
4.6.1. Avoid use of in-line isolation devices if other reasonable alternatives exist for
removal of a PRD.
BASF Corporation
McIntosh
Procedure
Title: Pressure Relief Device In-Line Isolation Device Control Procedure
Function: Safety
No.: MC032.020
Page: 4 of 4
Effective:
4.6.2.
11/2015
Supersedes:
11/2012
The opening through isolation valves shall have the same cross-sectional
area as the relief device so as not to constrict the flow
4.6.3. In-line isolation valves shall be capable of being locked.
4.6.4. If gate valves are used they should be installed so that the gate can not fall
off and block the flow.
4.6.5. A bleed valve should be installed between the isolation valve and the
pressure-relief device.
4.6.6. Consideration should be given to painting the isolation valves a special color
or providing them with some other means of positive identification.
4.6.7. The valve position should be easily determined upon inspection.
5
RELATED DOCUMENTS
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ZIM Gram #046 – Unsafe Isolation of Relief Devices
Attachment A – PSV Isolation List
Safety Critical Caution Tag