Deep Technical Chapters · Pressure Testing & Leak Diagnosis
Test Pressure — Time and Place for Different Pressures
Higher pressure is not automatically better. Choose the test pressure for the job — for the boundary, the components, and the purpose.
There is no universal Cold Fast test pressure. The right pressure depends on what you are testing, what is inside the boundary, and what you are trying to prove. A bigger number is not a better test — it can be a dangerous one.
What the pressure depends on
- Purpose of the test (leak detection vs integrity)
- The test boundary
- Component pressure ratings inside the boundary
- Valve arrangement
- System design
- Manufacturer requirements
- Applicable standards and procedures
Lower vs higher pressure
A lower-pressure test can be appropriate when diagnosing leakage while minimising differential pressure across an isolation valve — provided the pressure is suitable and permitted for that system and procedure. A higher-pressure integrity test can be appropriate when the entire intended boundary and every component within it are rated and approved for that pressure. The two are not interchangeable.
Field Rules
- 01
"Choose the test pressure for the job — not because a bigger number sounds better."
- 02
"Never use 100 psi or 600 psi as a universal Cold Fast test pressure."
Diagnosis at a glance
Common mistakes & callbacks
- •Defaulting to a high pressure without checking component ratings.
- •Using high differential pressure across a valve that may pass.
