Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-24 - General safety and health standards › Part I - WELDING, CUTTING AND BRAZING › Section 296-24-68209 - Protective equipment, hose, and regulators

Current through Register Vol. 24-14, July 15, 2024
(1)
General.
You must install
				and use only in the service for which it is approved and as recommended by the
				manufacturer.
(2)
Pressure
				relief devices.
You must protect service piping systems by pressure
				relief devices set to function at not more than the design pressure of the
				systems and discharging upwards to a safe location.
(3)
Piping protective equipment.
(a)The fuel-gas and oxygen piping systems,
				including portable outlet headers must incorporate the protective equipment
				shown in Figures Q-1, Q-2, and Q-3.
When only a portion of a fuel-gas system is to be used with
				  oxygen, only that portion need comply with (3)(a) of this
				  section.
(b) You must
				install approved protective equipment (designated PF in
				Figs. Q-1, Q-2, and Q-3) in fuel-gas piping to prevent:
(i) Backflow of oxygen into the fuel-gas
				supply system;
(ii) Passage of a
				flash back into the fuel-gas supply system; and
(iii) Excessive back pressure of oxygen in
				the fuel-gas supply system. The three functions of the protective equipment may
				be combined in one device or may be provided by separate devices.
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Fig. Q-1
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Fig. Q-2
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Fig. Q-3
LEGEND
PFProtective equipment in fuel gas
				  piping
VFFuel gas station outlet valve
VOOxygen station outlet valve
SFBackflow prevention device(s) at
				  fuel gas station outlet
SOBackflow prevention device(s) at
				  oxygen station outlet
(c)You must locate the protective equipment
				in the main supply line, as in Figure Q-1 or at the head of each branch line,
				as in Figure Q-2 or at each location where fuel-gas is withdrawn, as in Figure
				Q-3. Where branch lines are of 2-inch pipe size or larger or of substantial
				length, you must locate protective equipment (designated as
				PF) as shown in either Q-2 and Q-3.
(d)You must provide backflow protection by an
				approved device that will prevent oxygen from flowing into the fuel-gas system
				or fuel from flowing into the oxygen system (see SF,
				Figs. Q-1 and Q-2).
(e) You must
				provide flash-back protection by an approved device that will prevent flame
				from passing into the fuel-gas system.
(f)You must provide back-pressure protection
				by an approved pressure-relief device set at a pressure not greater than the
				pressure rating of the backflow or the flashback protection device, whichever
				is lower. You must locate the pressure-relief device on the downstream side of
				the backflow and flashback protection devices. The vent from the
				pressure-relief device must be at least as large as the relief device inlet and
				you must install it without low points that may collect moisture. If low points
				are unavoidable, you must install drip pots with drains closed with screw plugs
				or caps at the low points. The vent terminus must not endanger personnel or
				property through gas discharge; must be located away from ignition sources; and
				must terminate in a hood or bend.
(g) If pipeline protective equipment
				incorporates a liquid, you must maintain the liquid level, and a suitable
				anti-freeze may be used to prevent freezing.
(h) You must withdraw fuel gas for use with
				equipment not requiring oxygen upstream of the piping protective devices.