ES&H Manual



6151 Appendix T4

Pressure Systems Pressure Testing Program



This document is currently under review.  All requirements outlined within this document apply to current laboratory operations until new content is approved, released, and published.

1.0          Purpose


This appendix outlines the general requirements and provides a format for documentation of pressure test procedures performed on pressure vessels and leak tests performed on piping systems.  This appendix does not serve as a stand-alone reference.  The Design Authority is required to use the applicable codes to determine the appropriate test method.


2.0          Scope


Pressure testing and leak testing are required by applicable codes for pressure vessels and piping systems fabricated at Jefferson Lab.  For fabrications built by outside vendors, the Design Authority must verify that the testing has been conducted and that the recordkeeping requirements of this appendix are met.


Pressure/leak test procedures shall use the following references:

·       The ASME B31.3 Code 2002 (or current if more conservative) is to be used as a reference for pressure piping.  Other B31 Sections shall be used as appropriate based on the applicability of the design.

·       The ASME Boiler and Pressure Vessel Code 2004 (or current if more conservative) is to be used as the reference for pressure piping.


3.0          Responsibilities


3.1            Design Authority

·       Prepare the pressure test Operational Safety Procedure (OSP) or Temporary Operational Safety Procedure (TOSP).

·       Supervise and witness the pressure system test.

·       Ensure that all documentation of pressure testing is stored in the appropriate Pressure System Project Folder and Testing Sub-Folder and is accessible electronically.


3.2            Test Technicians

·       Install the pressure test setup.

·       Perform the pressure test under the direct supervision of the Design Authority.

·       Perform post-pressure test examinations.

·       Maintain the Pressure/Leak Test Worksheet.


3.3            Quality Assurance Inspector

·       Witness the pressure test for pressure piping and certifies that the pressure vessel satisfactorily passed the pressure testing.


4.0          Process Steps or Expectations


4.1            Work Control Documentation


The Design Authority shall determine whether an OSP or TOSP is required for the pressure test; and either use an existing OSP or prepare a new OSP or TOSP as applicable.  In the case of fabrication of more than one identical system, the OSP may address the pressure system of the entire lot.  ES&H Manual Chapter 3310 Appendix T1 Operational Safety Procedure (OSP) and Temporary OSP Procedure and ES&H Manual Chapter 3320 Temporary Work Permits contain general guidance for OSP/TOSP preparations.  A sample pressure test OSP is provided electronically in the Pressure Systems Directory in DocuShare.


            The Design Authority shall prepare a TOSP when the proposed testing has significant safety impacts.  Examples include, but are not limited to:

·       Pressure systems with stored energy greater than 100 kilojoules (kJ)

·       Pressure systems with P*V greater than 25 atm*cu ft for pressures up to 250 psi

·       Test pressure greater than 250 psi

·       Pressure systems whose working fluids are Category M as given in ASME B31.3


            In addition to the guidance provided in ES&H Manual Chapter 3310 Appendix T1 Operational Safety Procedure (OSP) and Temporary OSP Procedure and ES&H Manual Chapter 3320 Temporary Work Permits, the OSP/TOSP shall include:


4.1.1       Rationale for selection of test type (e.g. pneumatic vs. hydrostatic vs. initial service leak test).  (Note:  Initial service leak testing is permissible only for B31 pressure piping.  Initial service leak testing is not permissible for Section VIII vessels.)


4.1.2       Reference to applicable codes.


4.1.3       Special considerations required by the code.  Examples include but are not limited to:

·       Joint preparation considerations

·       Temporary supports

·       Special testing for expansion joints

·       Boundaries; disconnection methods for equipment not to be included in the test


4.1.4       Qualifications for the Test Technician shall be specified and may vary according to the ancillary hazards present in the test area (example oxygen deficiency hazards).  At a minimum, the Test Technician shall have:

·       Completed ES&H Orientation (SAF100)

·       Obtained ES&H Pressure Systems Hazard Awareness Training (SAF130A)

·       Read the pressure test OSP/TOSP

·       Signed the Pressure Test Worksheet


4.1.5       Protection of incidental personnel in the test area shall include:

·       Calculation of stored energy in terms of kilo-joules

·       Normal occupancy of the test area     Possible controls shall include:

o   Barricades

o   Shields

o   Scheduling of work for after the normal shift


4.1.6       Isolation Requirements for the test area shall include:     Post Danger signs indicating:

o   Pressure test is in progress

o   Only Authorized Personnel allowed to enter

o   Name and contact information of the test supervisor


4.1.7       Manifold connecting pressure supply with the test setup requirements shall include:     Vent valves (or bypass to liquid reservoir for hydrostatic testing) and locations     Regulator     Fill valve     Relief valve

o   Selected according to the applicable ASME code

o   Sized to provide adequate flow

o   Set to not exceed 120% of the required test pressure

o   Bench test the pressure relief device


4.1.8       Pressure gage requirements shall follow the requirements of “Measurement and Test Equipment Control and Calibration Procedure”.

·       Gages shall be calibrated.

·       Scale should preferably be double the intended maximum test pressure, but in no case shall the range be less than 1.5 or more than 4-times that pressure.


4.1.9       Inspection requirements for the assembled test setup.


4.1.10    Procedure shall be written in detail for the test.


4.1.11    Schematic of the testing installation shall be included.


4.1.12    A pressure test worksheet for the test, which is used with the procedure and serves as the test record (See Figure 1 for an example).


4.1.13    Approvals

·       Design Authority’s Group Leader

·       Industrial Safety

·       Test area supervisor

·       Division Safety Officer


4.2            Recordkeeping


The Design Authority is responsible for the following pressure testing recordkeeping requirements


4.2.1       Pressure Test OSP/TOSP


The signed-off OSP/TOSP shall be retained in the “Testing” folder for the appropriate pressure system in the Pressure Systems Directory on DocuShare and be readily accessible.


4.2.2       Pressure Test Worksheet


The completed Pressure Test Worksheet shall be retained in the Testing Folder for the appropriate pressure system and be readily accessible.  This verifies that the following data are maintained:

·       Date of test

·       Identification of piping system tested

·       Test fluid and pressure

·       Test examination procedures and results


4.2.3       Required Retention Time

·       Pressure vessels - for the life of the vessel

·       Piping systems - five years after the record is generated

5.0          Worksheet


Figure 1 - Pressure Test Worksheet Example


Pressure Vessel



Sensitive Leak Check


Text Box: •

Pressure Piping


Initial Service Leak Check

Alternate Leak Check


Test Date:


DocuShare  #:


Test Technician:


Signature indicates that test technician will comply with the OSP/TOSP.

Test Inspector:


For pressure vessels only.

System to be Tested :


Indicate if the vessel is tested in the vertical position.

Test Location:


Applicable Code:


OSP/TOSP number:


Certification by Inspector (for pressure vessels ) or by Test Technician (for pressure piping):


Certification that pressure system has satisfactorily passed the pressure test.




Allowable leak rate:






Working Fluid  Category


Normal, Category D, or Category M

Working Fluid



Working Temperature



Test Parameters



Test Fluid Category:


Normal, Category D, or Category M

Test Fluid:



Test Temperature:


Refer to the code: test temperature requirements may be required to exceed the minimum design metal temperature.

Relief valve setting:



Hold time:


Code requires a minimum time.

Test Pressure:


Refer to code.

Specify test pressure at the top of the vessel in the test position.

Test Pressure as percent of MAWP:


Calculate and verify compliance with code

Inspection Pressure:


Test Pressure ÷ 1.3 per ASME BPV Section VIII.

Design Pressure per B31

Post Test Inspection Requirements:


Refer to code.

Safety Controls



Stored Energy*


Used as one parameter to determine the degree of risk of a pneumatic test.

Relief Valve setting


Refer to code.

Relief Valve test


Calibrated within 1 year.

Relief Valve location


Recommend at high points to verify air pockets are purged.

Vents should point away from areas that have to be inspected.

Pressure Gage calibration date



Personnel Isolation devices




* Stored Energy Calculation:  The method of stored energy calculation must be detailed in the OSP/TOSP.  Stored energies greater than 100 kJ are considered to be high hazard.  This is equivalent to 0.0476 lb TNT.  An alternative P*V calculation can be performed to determine hazard level.  P*V greater than 25 atm*cu ft are considered high hazard and would require a TOSP.

5.1            For Gases


The stored mechanical energy of the test volume may be calculated using several methods.  These methods include the following:

·       Ideal Gas Laws

·       Brode equation for stored energy of a gaseous volume

·       Baker equation for stored energy of a gaseous volume (given below)

·       Aslonov-Golinsky equation for stored energy of a gaseous volume

·       Enthalpy tables

·       Equation stored energy of liquid


Design Authority shall determine the method most appropriate for determining the stored energy of the test volume.  If the system fluid is reactive, flammable, or explosive, the chemical potential energy must also be determined.  The stored energy of a pressurized fluid that is flammable or explosive is thus the sum of the chemical as well as mechanical stored energies.


5.1.1       Baker Equation


The stored mechanical energy of a gas may be calculated using the following expression:



NOTE:  Alternate units may be used (e.g. ASME PCC-2 Article 5.1) provided that they are consistent.


5.1.2       Equivalent Mass in TNT


The stored mechanical energy may be converted to an equivalent mass of TNT.  The following equation may be used to convert the stored energy of a system to pounds of TNT:



NOTE:  Alternate units may be used (e.g. ASME PCC-2 Article 5.1) provided that they are consistent.


5.1.3       Stored Energy of Liquid


The stored mechanical energy of a liquid that does not boil at ambient pressure and temperature may be calculated using the following equation:



The compressibility of water, at 10000 psi, is.  Similar fluids have compressibility of the same order of magnitude.  Thus, in many cases of moderate pressure, a good approximation of the stored energy is:

This expression should only be used for conditions where.  Note that it is readily apparent that the stored energy of a typical compressed liquid volume is much less than the equivalent volume and pressure of a typical gas.


5.1.4       Safe Distance Calculations for Pneumatic Test


The minimum safe distance between personnel and the equipment being tested shall be the greater of 3 ft and R which is determined by the following equation:



6.0          References


·       ASME Boiler & Pressure Vessel Code

·       ASME B31.3 Process Piping

·       ES&H Manual Chapter 3310 Appendix T1 Operational Safety Procedure (OSP) and Temporary OSP Procedure


7.0          Revision Summary


Revision 1.0  07/31/13 Replaced equations per DMeekins; adjusted formatting.

Revision 0.1  05/17/13 Added note in header to reflect current lab operations.









ESH&Q Division

Bert Manzlak




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