ANSI Z21.18:2007 pdf download.Gas Appliance Pressure Regullators.
2.5.1
Regulators shall be capable of withstanding, without deformation, breakage or leakage, the turning effort shown in Table Ill, exerted by assembling to piping or tubing.
This test shall not apply to regulators having flange connections.
Method of icst
A wrench of suitable size shall be used to apply the turning force. SAE 10 viscosity machine oil shall be applied to the taper threads of steel pipe nipples, which shall be inserted in the inlet and outlet of the regulator and turned up handtight. With the inlet nipple secured in a vise, the specified turning effort shall be applied to the outlet nipple. For other than straight through type regulators, the tests shall be repeated as outlined above except wilh the outlet nipple inserted in the vise and the turning effort applied to the inlet nipple. There shall be no evidence of deformation or breakage, or impairment of operation or capacity as a result of making up inlet and outlet connections.
Regulators designed for connection to tubing shall be tested as specified above except that the torque shall be applied to opposite ends of the regulator body through wrench flats or bosses and not to the tubing fittings.
After relaxation of the applied torque, the tests specified in 2.4, Leakage, shall be performed. NOTf: Any frof age due to dry threads shoft be disregarded.
2.5.2
A regulator shall be capable of withstanding the bending moment generated where subjected to the applicable static loads specified in Table IV,.
This test shall not apply to regulators having tubing connections.
Method of Test
The regulator under test and suitable lengths of standard weight pipe of the same size as the connections shall be made up into a pressure tight assembly. The inlet and outlet pipe shall be connected to an air pressure system capable of applying the test pressures as specified in 2.4, Leakage.
With the regulator In the upright position, the outlet pipe shall be clamped as close to the regulator as possible in a vise or other suitable rigid support. The appropriate static load specified in Table 1V. shall then be applied to the inlet pipe as close to the regulator as possible at a 90 degree (1.37 rad) angle from the direction of the outlet tapping. If the inlet and outlet connections are of different sizes, the static load for the larger size shall be applied.
While subjected to this load, the regulator shall be checked for external leakage In the manner prescribed in 2.4 and shall not exceed the allowable leakage rate specified.
2.5.3
For regulators rated in excess of /2 p1 (3.5 kPa), the bod atmospheric diaphragm chamber and sealing means of the regulator, except the diaphragm, shall withstand, without rupture, a static pressure of 5 times the rated inlet pressure.
The diaphragm employed In the regulator shall be substantially removed to permit the test medium to flow freely to both sides of the diaphragm.
The inlet and outlet of the regulator shall be connected to a suitable hydraulic system. The pressure shall be raised slowty to S times the rated inlet pressure of the regulator, or 7.5 psi (51.7 kPa), whichever Is greater, and held at that pressure for 1 minute.
2.6 Mounting Regulator For Test
Standard weight pipe (Schedule 40, API 5 L Grade B) of proper size, reamed to remove burrs caused by cutting, shall be properly fitted to the inlet and outlet connections of the regulator. When a regulator is provided with semirigid tubing connections, fittings and semirigid tubing of the proper size reamed to remove burrs caused by cutting shall be used instead of standard weight pipe.
The length of straight run of pipe before the inlet pressure tap shall not be less than 50 pipe diameters (ID.), or in accordance with the principles established for pipe tap connections as presented in Gas Measurement Committee Report No. 3, Edition, for the Orifice Metering ol Natural Gas. The length of straight wn of pipe between the regulator and any downstream controlling means shall be 10 pipe diameters (1,0.),
Three short lengths of pipe or metal tubing having a small diameter shall be soldered to the pipe or semirigid tubing, one before the inlet and the other two after the outlet connection. The pressure tap before the inlet shall be located S pipe diameters from the discharge end of the inlet pipe or tubing. The two pressure taps after the outlet connection shall be located 180 degrees (3.14 rad) apart and S pipe diameters from the inlet end of the discharge pipe or tubing. A ‘/ in (1.6 mm) diameter drill shall be inserted in each short length of pipe or metal tubing and a hole drilled through the wall of the larger pipe or semi4igid tubing, care being taken to remove any burrs caused thereby.
