Why choose OS&Y Gate Valve- NAFFCO-SHIELD

What is an OS&Y Gate Valve

OS&Y means "outside screw and yoke". It is very easy to be informed that either the valve is  open or closed by the position of the shaft. It is more difficult with an OS&Y globe valve because the shaft movement is short. A listed outside screw and yoke (OS&Y) gate valve shall be installed in the suction pipe. According to NFPA a listed indicating gate or butterfly valve shall be installed on the fire protection system side of the pump discharge check valve. No valve other than a listed OS&Y valve shall be installed in the suction pipe within 50 ft (15.3 m) of the pump suction flange. Listing is not mandatory for practical use.

Importance of using OS&Y Gate valve

to control water flow to fire sprinkler systems OS&Y gate valve is very important. Water supply for fire fighting system supposed to be from dedicated line. You cannot mix it up with domestic use. One quick look at an OS&Y valve with the stem raised out of the body of the valve and you will know that the water is on. On a typical gate type valve a visual inspection cannot determine whether the valve is open or closed. During the incident time every second matters. An OS&Y valve often controls access to the water source in a fire sprinkler or standpipe system

How an OS&Y Gate valve works

OS&Y gate valves operate by opening and closing via a gate, which lowers into or rises out of the valve. Raising the gate allows water to flow through the valve while lowering the gate cuts off the water flowing through the valve. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low friction loss.

Selection Criteria of OS&Y Gate Valve

Generally dia selection of OS&Y gate valve depends on pump capacity. In between the pump room there are 6 OS&Y gate valves required. 3 for suction line & 3 for delivery line. Its also required on the starting point of each riser. To follow NFPA a listed gate valve is required.

Why to Choose AXIS SAFETY as the supplier of OS&Y Gate Valve

Axis Safety Engineering Ltd supplies two types of OS&Y gate valves- Flanged Type & Grooved Type. These UL Listed valves are manufactured in accordance with the Standard UL 258 Valves, Trim and Drain components. The globe valves are intended to be installed by the National Fire Protection Association Standards, NFPA 13, 14 and 15. The valve utilizes ASTM B584 C84400 cast bronze for body, ASTM B124 C37700 forged brass for bonnet, disc holder and packing nut, ASTM B271 C86700 brass alloy for the stem, the handwheel is made of ASTM A126 Gr. B cast iron. The valve is intended for use in the water piping of fi re protection service in accordance with the Standard for the installation of Sprinkler System, NFPA 13, 14, 15. Rated pressure 175 psi, the leakage test pressure at both seat and body are 350 psi twice the rated pressure, hydrostatic test pressure 875 psi 5 times the rated pressure.

This gate valves are manufactured in UK, shipped from UAE under NAFFCO.

Axis Safety Engineering Ltd also do ready stock of SHIELD OS&Y gate valves.