It has come to our attention that some manufacturer(s) have changed the design of their auto purgers by installing a Relief Valve (RV) with the package. The owner’s manual of the component specifically lists the RV as a pre-assembled component and requires the installation of a “vent line” on this RV. This seems to be a considerable change from past designs and needs to be recognized for those facilities falling under PSM/RMP (as well as those not under PSM/RMP). Here is a breakdown of how this design change can impact a facility’s PSM/RMP program…
All models are preassembled, pre-wired, insulated, and include an automatic water bubbler, a relief valve, and an isolation service valve package. Installation requires piping the foul gas line, low-pressure pumped-liquid line, low-pressure liquid return line, suction line, water bubbler fills and drain lines, relief valve vent line, water purge line to a customer supplied container, and power connection, and wiring the remote purge point solenoid valves.
The manual goes on to say…
RELIEF VALVE VENT LINE
A relief valve vent line should be connected to appropriately vent any potential relief valve discharge in accordance with applicable codes, for example, ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.
Don’t let the “should be connected” wording above lead you to think this is a way out of the manufacturer’s requirements. The installation instructions require a relief valve vent line… and it “should” be designed to meet ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems. If our process falls under PSM/RMP there is no “should” and we must design it to an RAGAGEP such as ANSI/ASHRAE Standard 15, Safety Standard for Refrigeration Systems.
What does this mean to my PSM/RMP program?
First off we need to recognize this RV as another RV on our process and treat it like all the others. This means we may need to:
1. Have it listed on our RV listing of Critical Equipment
2. Ensure the vent line is SIZED properly
a. NOTE: if we tie this RV into our main RV header we will need to ensure our header is sized properly after the addition of this RV(s)
b. Keep in mind that some of these RV(s) are 3/4″ in size and could impact header sizing, especially if there are multiple purgers tied into a single header
3. Ensure the RV is in the MI inspection/testing or replacement schedule
4. This needs to be included in the PHA revalidation
5. This needs to be included in our PSI “safety systems”
6. This needs to be included in our SOPs for the purgers as “safety systems”
These new purgers are very nice and should be considered a UPGRADE and it is up to us AND the installers to be aware of the manufacturer’s install and maintenance requirements. I can attest that if one of these devices release NH3 into your work area it is easy for OSHA or EPA to refer to the owners manual and make the argument the equipment was NOT installed per manufacturer’s instructions (e.g. RAGAGEP).