AS 2022:1983 pdf – SAA ANHYDROUS AMMONIA CODE.
All removable fittings shall be secured by chain.
2.3.5 Filling and I)lscharge Connections. Each connection shall be provided with a screwed cap or plug. secured by a chain, and incorporating a vent hole arranged so that it becomes uncovered when the cap is partly unscrewed, giving warning of leakage or pressure within the tilling.
2.3.6 Valves and Fittings. Any valve, tilling or accessory used for anhydrous ammonia service shall comply with AS 1271. as appropriate, for a design pressure of 1.73 Mpa. and in addition to complying with the marking requirements of AS 1271. shall be clearly and pennanently marked AA’.
2.4 PRESSURE-RELIEF
2.4.1 Provision of Safely ‘ahes. Each tank shall be provided with at least one safety valve, which shall be in direct communication with the vapour space of the tank ss hen the tank is at rest in its normal operating position.
2.4.2 Set Pressure. Safety valves shall be set to start to discharge in accordance with the requirements of
AS 1210.
2.4.3. Locking or Scaling. Safety valves shall be arranged so that the possibility of tampering will be minimized. Where the pressure sciting or adjustment is external, the safety valve shall be provided with a means of sealing the adjustment.
2.4.4. Discharge Capacity. The aggregate discharge capacity of any safety valves shall he not less than that determined in accordance with Appendix H.
NOTF Appendix B has not been derived from ihe more general tiwmula gnen in AS 1210. simplified 10 treat the speeifw case of anhydrous ammonia.
2.4.5 Reserve Safety akes. Where additional safely valves are provided for servicing convenience, the valve system used to isolate any such devices shall be designed so that i not at any time possible to operate the system with less aggregate pressure-relief capacity than that required under Clause 2.4.4.
2.4.6 liquid Relief Vahes. A relief valve shall be installed between each pair of shut-off valves on anhydrous ammonia liquid piping, so as to relieve hydrostatic pressure to atmosphere. The start-to-discharge pressure of such valves shall be not less ihaii 2.4 Mpa and not greater than 3.5 Mpa.
2.5 EXCESS-FLOW VALVES AND NON-RETURN VALVES.
2.5.1 General. Every vapour or liquid opening in a tank shall be provided with an internal excess-flow valve, or where flow is inward only, with an internal non-return valve, except that excess.flow valves or non. return valves are not required on the following:
(a) Openings to which safety valves are fitted.
(b) Plugged openings.
(c) Openings not greater than 1.4 mm diameter.
(d) Vapour bleed and liquid withdrawal openings of applicator tanks of I m1 capacity or less which are mounted on farm vehicles and used for the application of anhydrous ammonia.
AS 2022:1983 pdf – SAA ANHYDROUS AMMONIA CODE
