WAC 296-826-60020   General specifications.  

     You must:

     • Get owner authorization to use transfer containers.

     • Make sure transfer containers are gauged and filled in either:

     – Open atmospheres;

     OR

     – Buildings approved for that purpose.

     • Make sure pumps used to transfer ammonia meet all of the following:

     – Have a manufacturer's label for ammonia service

     – Are designed for at least 250 psig working pressure

     – Have a constant differential relief valve discharging into the suction port that:

     ▪ Is installed on positive displacement pumps;

     AND

     ▪ Meets the pump manufacturer's recommendation for the settings and installation

     – Have a pressure gauge graduated zero to 400 psig installed on the discharge side before the relief valve line.

     • Make sure plant pipes with shut off valves are located as close as possible to the pump connections.

     • Make sure meters used for measuring liquid anhydrous ammonia:

     – Are recommended and labeled for ammonia service by the manufacturer

     – Are designed for a minimum working pressure of 250 psig

     – Incorporate devices that prevent unintended measurement of vapor.

     • Do the following when transferring ammonia:

     – Maintain ammonia at a temperature suitable for the receiving container

     – Have at least one attendant supervise the transfer from the time connections are made to when disconnection occurs

     – Do NOT use flammable gases or gases that will react with ammonia, such as air to unload tank cars or transport trucks.

     • Make sure compressors used for transferring ammonia meet all of the following:

     – Have a working pressure of at least 250 psig when transferring ammonia.

     ▪ If crank cases of compressors are not designed to withstand system pressure, then provide protection with a suitable safety relief valve

     – Are connected to plant piping with shut off valves located as close as practical to compressor connections

     – Have a safety relief valve that is both:

     ▪ Large enough to discharge the full capacity of the compressor;

     AND

     ▪ Connected to the discharge before any shut off valve

     – Have an oil separator on the discharge side, where necessary to prevent contamination

     – Have a drainable liquid trap or other adequate method on the compressor suction to minimize the entry of liquids into the compressor

     – Pressure gauges on the suction and discharge ends graduated to at least one and one-half times the maximum pressure that can develop.

     • Protect loading and unloading systems in the event of hose severance by suitable devices where necessary, such as:

     – Backflow check valves;

     OR

     – Properly sized excess flow valves.

Note:

If such valves are not practical, remotely operated shut off valves may be installed.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, 49.17.060. 06-10-067, § 296-826-60020, filed 5/2/06, effective 9/1/06.]