Pneumatic Testing Procedures

Format of Pneumatic Test Procedure

  1. Test procedures ≤ 1677 kJ stored within the pneumatic test limitations may be developed and submitted by a licensed contractor using an application-specific or standard pneumatic test procedure format.
  2. Pneumatic test procedures > 1677 kJ that are not within the pneumatic test limitations shall be developed using an application-specific procedure. The application-specific procedure shall be developed and approved by a professional engineer and submitted to Technical Safety BC for acceptance prior to conducting the test.

Standard Pneumatic Test Procedure

Licensed contractors who frequently perform pneumatic pressure tests may include an accepted pneumatic test procedure ≤ 1677 kJ that is within the stored energy, temperature and pneumatic test limitations in their quality control manual. The addition of the procedure will constitute a revision to the Quality Control Manual (QCM). The licence holder shall submit their QCM to Technical Safety BC for review and acceptance. Revisions are normally submitted to the regional boiler safety officer. The standard test procedure shall be acceptable for subsequent pneumatic tests within the limitations of the accepted procedure.

Witnessing of Pneumatic Test Procedures

Where a safety officer witnesses a pneumatic test, the licence holder must establish a pneumatic testing procedure that addresses all the safety considerations necessary to conduct the test safely and ensure the safety of those present at the workplace (Workers Compensation Act Section 115 1(a)(i)).

The following outlines minimum procedure requirements for licence holders seeking acceptance of a pneumatic test procedure. Additional items may be required depending on the specific system, equipment, and code of construction.

  • An overview of the process is found in a flow chart at the end of this document.

Definitions

  1. an expansible fluid, or
  2. a non-expansible fluid or thermal fluid with an operating temperature exceeding 121°C or a working pressure exceeding 1,100 kPa between 2 or more points
application- specific test procedure

A job-specific test procedure, applicable to one site, created for a specific use.

design pressure The pressure authorized on the design registration.
MAWP maximum allowable working pressure.
pneumatic test A pressure or tightness test where a gas – generally nitrogen or air – is the test medium.
pressure piping A system of pipes, tubes, conduits, gaskets, bolts, and other components that have the sole purpose of conveying
pressure vessel A vessel used for containing, storing, distributing, processing, or otherwise handling an expansible fluid under pressure.
professional engineer A person who holds a degree in mechanical engineering accredited by the Canadian Engineering Accreditation Board and is registered as a professional engineer.
Quality Control Program (QCP) A conformity assessment program registered with Technical Safety BC detailing the scope of work performed by the licensed contractor and establishing how all requirements of The Act, Regulations and applicable codes will be met. A written Quality Control Manual (QCM) is the document submitted to Technical Safety BC for acceptance.
safe distance To prevent any injuries, safe distance is the minimum distance between all personnel and the equipment being tested. This distance is based on the potential blast wave distance and is maintained to minimize the risk of fragments of the vessel or piping impacting personnel.
standard pneumatic test A leak test of a pressure system using air or nitrogen, conducted by an organization holding a Technical Safety BC contractor licence. The test must use a procedure referenced in the organization’s Quality Control Manual (QCM) that is within the stored energy, temperature, and material limitations established in this document.

General

The hydrostatic test method is the mandated and preferred method of pressure testing. Hydrostatic testing presents a much lower safety hazard associated with the stored energy compared to pneumatic testing. Where a hydrostatic test is considered to be impracticable, a pneumatic test in accordance with the construction code may be substituted. The licensed contractor must justify the rationale for, and seek acceptance from Technical Safety BC for the alternative test. Acceptable reasons for using a pneumatic test may include the following:

  • the system cannot be readily dried and is used in services where traces of testing fluids cannot be tolerated
  • the equipment is so designed or supported that it cannot be safely filled with water

Hazard Identification

The procedure must identify environmental and operational hazards associated with pneumatic testing.

Roles and Responsibilities

The procedure must identify the individual who is responsible for ensuring that the requirements of the procedure are properly implemented and empower all personnel with authority to stop work whenever hazardous conditions are identified.

Pneumatic Test Limitations

Identify that the scope of equipment is within the following test limitations:

  • The stored energy value will not exceed 1677 kJ.
  • The pressure system is made of P-1, P-8 material or a material acceptable to Technical Safety BC that conforms to a specification listed in the code of construction.
  • The test medium is air or nitrogen.
  • The testing will be conducted at a temperature of at least 17°C (30°F) above the design metal’s minimum temperature.
  • Any additional requirements appropriate to the code of construction.

Pneumatic test procedures that are not within the Pneumatic Test Limitations shall be developed using an application-specific procedure. The application-specific procedure shall be developed and approved by a professional engineer and submitted to for acceptance prior to conducting the test

The procedure must:

  • Require that affected personnel fully understand the process, potential hazards, and protective measures.
  • Describe the use of any specific personal protection equipment (PPE) that may be needed to safely perform or witness the test (e.g., face shields at a manifold station).

Exclusion Zone

The procedure must:

  • Describe precautions to be taken so that unauthorized persons remain out of the test area during the test period.
  • Prescribe a minimum safe distance to be maintained.
    • Consideration must be given to establishing the minimum safe distance limit for personnel during the pneumatic test. The minimum safe distance of 30 meters, based on PCC-2 Article 5.1 Mandatory Appendix III and using the standard pneumatic test values, may be used.
    • Alternatively, unless the hazard assessment suggests otherwise, the licensed contractor may reduce this safe distance limit by:
      • installing properly designed and fabricated barriers capable of withstanding the sudden release of stored energy should the system fail, or
      • placing the test item in an engineered enclosure, or
      • calculating the minimum safe distance using another recognized standard, or
      • taking other measures to minimize the risk of harm to personnel.
    • Restrict access to the immediate area involving the pressure test (i.e., test shelter, manifolds, instruments) to only those who are actively engaged in the testing operation.

Pre-Test Checks and Inspections

The procedure must describe a pre-test inspection to verify the following, where appropriate:

  • The system is completed according to drawings and specifications.
  • All visual inspections and non-destructive examinations required by the code of construction shall be completed and evaluated as acceptable.
  • Parts of the system not being tested are adequately isolated.
  • A pre-test inspection shall be made to verify proper assembly and tightness of connections, positioning of valves and all supports are installed as designed.
  • Proper assembly, including tightness of connections, positioning of valves, over pressure protection and hangers and supports are in place as designed.
  • There is no damage, misalignment or anything else out of place.
  • All associated lockouts are in place.
  • Any hoses are restrained or anchored and whip checks are in place.

Final Preparation

The procedure must:

  • Describe the test pressure value and verify that it is the minimum in accordance with the code of construction (usually 110% of the design pressure).
  • Require that gauge(s) are calibrated and that the appropriate range is used (1.5 – 4 times of test pressure).
  • Require that metal temperature is satisfactory at test time.
  • Require that the safe distance, as identified in the test procedure shall be identified by placing appropriate barriers to restrict non-essential personnel from the test area.
  • Require that overpressure protection is in place and set to the lesser of 50 psi or 10% above the test pressure.

Testing Activities

The procedure must:

  • Describe a graduated pressurization method to reach test pressure, including minimum durations to hold the pressure at each graduated step.
  • Require that the test pressure be reduced to design pressure before examining for leakage.
  • Require that if leaks are identified, the system shall be de-pressurized prior to proceeding with repairs or correction of the deficiency.
  • Require that depressurization must take place in a controlled manner and the dangers of a confined space and possibility of asphyxiation from the test medium (such as nitrogen) are considered.

Documentation

The procedure must:

  • Provide exhibits for all required forms and test reports. Detail a method for documenting the procedure as well as final results.
  • Require authorization of the test report by the contractor and the owner’s representative or safety officer.

Test Pressure

Test pressures must be determined using the rules from the code of construction. The lowest permissible test pressure shall be used.

Stored Energy Calculation

The stored energy for the pneumatic test may be calculated using the method provided in PCC-2, Part 5, Article 5.1 Mandatory Appendix II:

If the calculated E is > 1677 kJ, the pneumatic test procedure must be developed and approved by a professional engineer. The procedure must be accepted by Technical Safety BC.

The stored energy may be calculated using the following formula providing that nitrogen or air is used as the test medium:

E=2.5 x Pat x V [1 – (Pa/Pat)0.286 ]
Where:

E = stored energy in kJ
Pa = absolute atmospheric pressure, 101 kPa Pat = absolute test pressure in kPa
V = total volume under test pressure in m3

Test Procedure Volume Limits

Test procedure limits are calculated using method A or method B below based on the design pressure and the volume of the system undergoing testing. The calculation outcome will result in relatively higher volume for lower pressure and conversely lower volume for higher pressure while maintaining the accumulated stored energy of 1677 kJ.

Step 1

Define system DESIGN PRESSURE (DP) and VOLUME (V).

Step 2

Calculate system TEST PRESSURE (TP) using rules from the code of construction.

Step 3

Using the value of TP calculate the VOLUME LIMIT (V1) for the test applying one of the following two methods:

Method A

If Imperial units are used, calculate V1 using TP in psi

Pneumatic Testing - Method A-1

 

Or, if SI (Standard Imperial) units are used, calculate V1 using TP in kPa

Pneumatic Testing - Method A-2

 

Method B

Calculate V1 using values from Table 1 and apply the following interpolation

Pneumatic Testing - Method B

Where:

DP

– design pressure in psi or kPa

TP

– test pressure in psi or kPa

V

– total volume of the pressure system in ft3 or m3

TPA

– the first smaller pressure value in Table 1 than the step 2 TP value

TPB

– the first larger pressure value in Table 1 than the step 2 TP value

VA

– the corresponding Table 1 volume listed in same row as TPA

VB

– the corresponding Table 1 volume listed in same row as TPB

V

– calculated volume limit in ft3 or m3

 

For Volume Limit (V1), Method B shows from 0 to 3% lower values than Method A.

Table 1

       

Imperial Units

 

 

SI Units  

Test

   

Test

 

Pressure

Volume

 

Pressure

Volume

psi

ft3

 

kPa

m3

15

615.90

 

103

17.440

20

441.00

 

138

12.488

25

342.92

 

172

9.710

30

273.68

 

207

7.750

40

194.50

 

276

5.508

50

145.27

 

345

4.114

75

90.11

 

517

2.552

100

66.07

 

689

1.871

125

50.77

 

862

1.438

150

41.39

TPA & VA

1034

1.172

175

34.21

TPB & VB

1207

0.969

200

29.58

 

1379

0.838

225

25.80

 

1551

0.731

250

22.84

 

1724

0.647

275

20.47

 

1896

0.580

300

18.52

 

2068

0.524

315

18.0

 

2172

0.500

325

16.90

 

2241

0.478

350

15.52

 

2413

0.440

375

14.35

 

2586

0.406

400

13.33

 

2758

0.378

450

11.66

 

3103

0.330

500

10.35

 

3447

0.293

600

8.43

 

4137

0.239

700

7.10

 

4826

0.201

800

6.11

 

5516

0.173

900

5.37

 

6205

0.152

1000

4.73

 

6895

0.134

1500

2.97

 

10342

0.084

2000

2.21

 

13790

0.063

 

Step 4

Compare V and V1

If V ≤ V1, the test limits are within the 1677 kJ threshold and the procedure may be developed by the licensed contractor and submitted to a safety officer for review and acceptance.

If V ≥ V1, the pneumatic test procedure must be submitted to: boiler.designregistration@technicalsafetybc.ca for review and acceptance.

Flowchart
pneumatic testing flowchart