ANSI Z21.18:2000 pdf download.GAS APPLIANCE PRESSURE REGULATORS.
13 ASSEMBLY 13.1 Air movement (breathing) from the atmospheric side of the regulator diaphragm shall take place only through the vent opening(s). 13.2 The construction of parts not covered by this standard shall be in accordance with reasonable concepts of safety, substantiality, durability and interchangeability. All specifications as to construction set forth herein may be satisfied by the construction actually prescribed or such other construction as will provide at least equivalent performance. 1.4 CONNECTIONS 1.4.1 When for connection to pipe, connections shall be provided with cleanly cut taper pipe threads in accordance with the Standard for Pipe Threads, General Purpose (Inch), ANSIASME B1.20.1. 1.4.2 When a pressure test gage connection is provided as a part of the regulator, this pressure test gage connection shall be: ; A tapping sealed by a minimum ‘1g inch NPT plug or cap with cleanly cut taper pipe threads in accordance with the Standard for Pipe Threads, General Purpose (Inch), ANSI/ASME B1.20.1. If the plug is of the slotted type it shall also incorporate square or hex fats; or b. A hose ftting which incorporates a captured sealing means. The ftting shall have a minimum length of 0.355 inch (9.02 mm) and a 0.355 inch (9.02 mm) maximum/.335 inch (850 mm) minimum outside diameter. 1.43 Pipe thread length and length to shoulder dimensions shall not be less than shown in Table I.
1.4.5 When for connection to semi-rigid tubing, the connection, together with the fttings used thereon shall be in accordance with or be interchangeable with the fttings described in Volume 1- Materials, SAE Handbooks, or equivalent. 1.4.6 Standard flange connections, when provided, shall be constructed in accordance with the dimensional specifications for 125-1b cast-iron fanges of the Standard for Cast lron Pipe Flanges and Flanged Fitings, Class 25, 125, 250, and 800, ANSUASME B161. (See Fgure 1.) 1.5 BOLTS AND SCREWS The threads of all bolts, nuts and screws used in the assembly shall be in accordance with the Standard for Unjfied Inch Screw Threads (UN and UNR Thread Form), ANSIASME BI.I. 1.6 ADJUSTMENTS 1.6.1 Adjustable type regulators and the adjustable stages of multi-stage regulators shall be provided with means for making any necessary adjustment of outlet pressure. The adjustment means of spring-type regulators shall be concealed.ANSI Z21.18 pdf download.