Field Test Procedures and Equipment Use
The kit
A field test kit centers on a differential pressure gauge readable to 0.1 psi, with hoses, tees, adapters, needle valves, and a sight tube for relief discharge. Gauges must be calibrated - commonly annually - against a reference and must be in good condition; a damaged lens or bent needle is grounds to reject the kit. Confirm the gauge range covers the pressures you will read before you start.
Procedure discipline
Identify the assembly and its test cocks. Flush each test cock before connecting. Bleed air from hoses - trapped air produces erratic readings and is the single most common field error. Always test in the manufacturer's and AHJ's prescribed sequence and record each reading as you take it, not afterward.
Acceptance criteria to know
- RPZ: check valve #1 must hold against a 1.0 psi differential; check valve #2 must hold at 1.0 psi; the relief valve must open at a differential of at least 2.0 psi below the supply-side reading.
- DCVA: both check valves must hold at 1.0 psi.
- PVB: the check valve must hold at 1.0 psi and the air inlet must open to atmosphere when the check does not hold.
Traps to expect
- Connecting to the wrong test cock (high side to #1, low side to #2 on an RPZ).
- Failing to flush or bleed, then reporting a false failure.
- Testing while a downstream demand or fire flow is running.
- Forgetting to note relief discharge observed during the check #1 leak test.
Rule of thumb
"Flush, connect, bleed, read, record." Worked example: on an RPZ, if the relief valve discharges continuously while test cock #2 is open and the gauge shows no differential, suspect check #1 is not holding rather than a failed relief valve.