The RPZ test report form, field by field

A reduced pressure principle assembly (RP, commonly written RPZ) has two independent check valves and a differential relief valve between them. A report that only records "passed" proves nothing: the value of the document is the measured numbers, the identity of the assembly they came from, and the traceability of the person and gauge that produced them. Every complete report carries five blocks.

• Inspection and facility — customer or facility name, service address, contact and phone, the water purveyor receiving the report, meter or account number, assembly location notes, test date, and the reason for the test (annual, initial, post-repair, survey).
• Assembly identification — type, manufacturer, model, serial number, size, service type (domestic, irrigation, fire protection, boiler, process) and hazard classification. Serial number is what ties this year's test to last year's.
• Initial test readings — check #1 differential, relief valve opening point, check #2 tightness against backpressure, both shutoff valves, and static line pressure.
• Repairs and final retest — only when the initial test failed: what was done, and the complete second set of readings.
• Tester, gauge and signatures — certification number and expiration, company and license, differential gauge make, model, serial and calibration date, then the tester signature and, where required, the site representative's.

Print this or work down it on the screen. The order matches the order the generator asks for it, which is also the order that avoids walking back to the truck.

Procedures are published by the certifying and regulating bodies and by the assembly manufacturer, and they differ in detail. What follows is the ordinary shape of a three-valve differential gauge test on an RP so you know which blank gets filled when — not a substitute for the procedure your certification and purveyor require.

1. 1

   Identify and inspect before you hook up

   Read the tag: type, make, model, serial, size. Note the installation — orientation, clearance, relief port discharge, and anything you will have to describe in the location notes.

2. 2

   Record static line pressure and flush the test cocks

   Note supply pressure, then flush each test cock so debris does not end up in the gauge or under a check.

3. 3

   Test check valve #1

   Attach the gauge, bleed the hoses, then measure the differential across the first check. Baseline pass is 5.0 PSID or greater, and the reading must be stable, not falling.

4. 4

   Test the differential relief valve opening point

   Measure the differential at which the relief valve begins to discharge. Baseline pass is 2.0 PSID or greater.

5. 5

   Calculate the buffer before you pack up

   Check #1 minus relief opening. Below 3.0 PSID the assembly is marginal — it is far cheaper to service it now than to be called back. BackflowPass shows this number in large type as you type the two readings.

6. 6

   Verify check valve #2 against backpressure

   Apply backpressure per your procedure and record tight or leaked. This is a condition, not a differential, so it is reported in words on the sheet.

7. 7

   Verify both shutoff valves and restore service

   Record each as tight or leaked, close test cocks, restore the service, and confirm no relief discharge under normal operation.

8. 8

   Sign the report on site

   Certification number, gauge serial and calibration date, signature, and the site representative where your program requires it. Signing on site is what makes a same-day submittal possible.

These are the thresholds BackflowPass ships with, read directly out of its rule engine. They reflect common field practice for reduced pressure principle assemblies. They are held in one configurable rule set, so a jurisdiction with different limits is a configuration change rather than a workaround.

A missing reading is reported as incomplete, never as a failure — an unrecorded number is not evidence of a defect. The overall result is always derived from the readings; there is no box to tick that declares an assembly passed.

Buffer is the reading most often left off a paper form, and the one that most often explains a callback. Same two thresholds, two very different assemblies:

Both assemblies pass every individual threshold. Assembly B is the one you want to service on this visit. You can put your own numbers through the same math on the interactive pass/fail calculator.

A failure is not the end of the report — it is the start of the second half of it. The document has to preserve what failed, what you did, and what the assembly measured afterwards.

Common RP failures and the usual cause

• Check #1 below minimum — debris or scale on the seat, damaged rubber, or a weak spring. Clean, then re-measure before replacing parts.
• Relief opening below minimum — fouled seat or a tired relief spring. Flush and service the relief; rebuild if it will not hold a stable opening point.
• Buffer too small — usually a relief opening creeping up rather than a check going soft. Service the relief first.
• Check #2 leaks under backpressure — debris or a nicked disc. This is the failure that most often follows upstream work on the system.
• Shutoff leaks — the readings taken through it are not defensible. Repair or replace the shutoff, then retest from the top.

What the retest block records

The repair actions performed (cleaned checks, replaced rubber or disc, replaced spring, serviced or rebuilt the relief, other with notes), then the full second reading set. A passing retest is reported as passed after repair — a distinct outcome from a first-pass result, and one the property owner and purveyor are both entitled to see. If any retest reading is missing, the record stays incomplete rather than quietly reporting a pass.

There are two ways to work. Use the checklist above as your paper structure and transcribe later, or open the generator, pick RP, and let the form ask for exactly these fields in this order. The generator grades each differential as you type, calculates the buffer, opens the repair and retest section the moment something fails, takes both signatures on the screen and exports a one-page PDF — offline, with no account.

• The reading fields shown are only the ones an RP uses, so there is nothing irrelevant to scroll past in a vault.
• Your certification and gauge details are filled in from your profile, and can be overridden for a single test when you borrow a kit.
• The finished report fits one 8.5×11 portrait page — no spillover, no second sheet to lose.
• Next year, start the annual from last year's record: identity fields carry over, readings start blank, and the old report is preserved.