Brass Needle Valve 1/4″ MNPT x 9-16-18 Left Hand – certified for LP Gas – Propane – up to 350 psi. This valve has a knurled brass handwheel and can be used on gas or liquid. Each valve is pressure tested at the factory. The stem is stainless steel with a fine thread for controlling flow with a positive shut-off. Gas flow is one way only.