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3-29 Pressure Test System - Cont'd.
procedures below allow for three different test medias, air, water or fuel. The media used is dependent on the conditions
at the specific site and installation/operations management decision. From a safety standpoint, a water test is preferred;
however, it has certain disadvantages. Although a fuel test is inherently more risky, it can be handled safely if extreme
care is taken and the method will save time. If a fuel pressure test is conducted, it can be handled in conjunction with the
purge and commissioning programs outlined in Chapter 4. A complete test is recommended; however, it is understood
that some deviation at the discretion of qualified operating management may be required due to specific site conditions
and immediate operating needs.
3-29.1
Test Media. Testing may be done with water, compressed air or fuel. The decision as to which test medium
to be used must be based on site conditions and operating need.
There are advantages and disadvantages to the use of each:
a.
Water. Testing with water is safer, and leaks are easier to find, but there are some disadvantages.
1)
Water may not be available for packing the system in some areas.
2)
Water expands as it freezes. It should not be used if the ambient temperature is expected to drop below
freezing during the test. A glycol or alcohol antifreeze, if available, may be added to lower the freezing temperature.
3)
All water must be removed and system dried out prior to its being packed with fuel. It is not recommended
that the fabric collapsible tanks be tested with water due to the difficulty of removing the water.
b.
Compressed Air. If testing with water or fuel is impossible, the test may be made with compressed air. Test
pressures with air must be lower. Se 3-29.2 below. It is not considered safe practice to attempt to test fabric collapsible
tanks with air.
WARNING
Air can b used to test clean, vapor free lines only. Never put air in line after fuel use, unless
they have been thoroughly cleaned and purged. Air mixed with fuel vapor is a dangerous fire
hazard.
c.
Fuel. Since there are some problems when testing with water or air, testing can be done with fuel. Several
conditions should be met when testing with fuel.
1)
All fire suppression equipment should be in place and in operating condition.
2)
Buildings near the section under test should be vacated and well ventilated.
3)
The test section should be under constant surveillance during test.
3-29.2
Maximum Test Pressures
a.
General. Testing is for locating leaks, loose connections, blockage in system and flaws in construction. Testing
will prove the integrity of the facility prior to regular operation.
3-24
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