Needle Valves by Metal Goods Mfgr. Co.

No. 19 Series MGM 1/8 in. & 1/4 in. Needle valves

These valves are built for service up to 1500 pounds, which is approximately the highest pressure at which the stem can be turned easily inward against the pressure. However, wall thicknesses are sufficient to withstand pressures of many times this amount.

Each valve has a replaceable telfon tip on the end of the stem and replaceable o-ring packing.

The Teflon tip is replaced easily by unscrewing the bonnet from the body, removing the tip by cutting a gash into one side with a knife and pulling it off the stem, slipping a new tip on the stem, replacing the bonnet in the body, (not tightly), and screwing the stem downward to force the tip onto the stem. The bonnet can be removed for inspection before screwing it tightly into the body.

The O-ring packing is replaced easily by unscrewing the bonnet from the body, screwing the stem downward until the O-ring is exposed, removing the old O-ring, slipping a new O-ring into place on the stem, screwing the stem upward as far as it will go and replacing the bonnet snugly into the body. A wrench should be used but the bonnet should not be tightened too tightly into the body as this may bind the stem. A small amount of sealing compound may be placed on the bonnet before screwing it into the body. Do not use sealing compound on the ()-ring.

Packing is a synthetic O-ring of a formula suitable for the liquid for which the valve is to be used. The packing is located between the fluid chamber and the thread of the valve stem and bonnet so the thread can be lubricated. The lubrication will not be washed out by the liquid within the valve.

Full flow valves have a large hole through the body for fast flow where close flow control is not needed. Fine flow valves have a small hole through the body for fine flow and close control. However, when the valve is closed, the Teflon tip will compress slightly, and when the valve is opened for very fine flow, the Teflon will expand slightly to regain its original shape, which may cause the flow to diminish or cease. Slight adjustment, when the Teflon fully regains its original shape, will correct the rate of flow.

Straight body valves are made of either stainless steel or brass. Angle body valves are made of stainless steel only. The customer should designate the material required as follows: SS for stainless steel or BR for brass, following the model letter and separated from it by a diagonal. Example: NO. 19A/BR is a NO. 19A valve made of brass. Brass valves have stainless steel stems, bonnets, and handwheel pins.

Valves in this series (with the exception of NOS. 19ZA and 19ZB) have American Standard male and female pipe threads. Valves with male pipe threads have tapered seats to fit MGM UNIVERSAL FITTINGS. NOS. 19ZA and 19ZB have 1/4-18 NPT male threads on the inlet end, and 9/16-18 NF male threads on the outlet end.

DO NOT USE A WRENCH TO TIGHTEN THE STEM AGAINST THE SEAT.

When ordering, the customer should state the model number, the material from which the valves are to be made (Brass (B) or Stainless Steel (SS)), and the liquids for which they are to be used.