2020 New Style Screwed Gate Valve - Flanged Gate Valve – Newsway

Flange Gate Valve

Key works: Flange, Gate, Valve, WCB, CF8, CF8M, C95800, class150, 300, 600lb,  4A , 5A, 6A, os&y, bolt, bonnet, rising, stem

PPRODUCT RANGE:

Sizes: NPS 2 to NPS 60

Pressure Range: Class 150 to Class 2500

Flange Connection: RF, FF, RTJ

MATERIALS:

Casting: (A216 WCB, A351 CF3, CF8, CF3M, CF8M, A995 4A, 5A, A352 LCB, LCC, LC2) Monel, Inconel, Hastelloy,UB6

STANDARD

Design Features:

1. Full or Reduced Bore
2. RF, RTJ, or BW
3. Outside Screw & Yoke (OS&Y), rising stem
4. Bolted Bonnet or Pressure Seal Bonnet
5. Flexible or Solid Wedge
6. Renewable seat rings

Flange gate valve is a gate valve with flange connection, this connection method is the most common. Flange gate valves are stable and reliable when used in pipelines, so flange gate valves are often used in high-pressure pipelines.

When the flange gate valve is closed, the sealing surface can only rely on the medium pressure to seal, that is, rely on the medium pressure to press the sealing surface of the gate to the valve seat on the other side to ensure the sealing of the sealing surface, which is self-sealing. Most gate valves use forced sealing, that is, when the valve is closed, the gate must be forced against the seat by external force to ensure the sealing of the sealing surface.

The gate of the gate valve moves linearly with the valve stem, which is called the lifting stem gate valve (also called the rising stem gate valve). Usually there is a trapezoidal thread on the lifting rod. Through the nut on the top of the valve and the guide groove on the valve body, the rotary motion is changed to linear motion, that is, the operating torque is turned into operating thrust.

When the valve is opened, when the lifting height of the gate is equal to 1:1 times the valve diameter, the fluid passage is completely unblocked, but this position cannot be monitored during operation. In actual use, the apex of the valve stem is used as a mark, that is, the position where it cannot be opened, as its fully open position. In order to take into account the locking phenomenon due to temperature changes, the valve is usually opened to the apex position and then rewinded by 1/2 to 1 turn as the fully open valve position. Therefore, the fully open position of the valve is determined by the position of the gate (ie stroke>.

In some gate valves, the stem nut is set on the gate, and the rotation of the handwheel drives the rotation of the valve stem to lift the gate. This kind of valve is called a rotating stem gate valve or a dark stem gate valve.

Installation of flange gate valve:

1. Check the inside of the valve cavity and the sealing surface before installation, and no dirt or sand particles are allowed to adhere;

2. The bolts of each connection part shall be evenly tightened;

3. Check the packing parts to be pressed tightly, not only to ensure the tightness of the packing, but also to ensure the flexible opening of the gate;

4. Before installing the valve, the user must check the valve model, connection size and pay attention to the flow direction of the medium to ensure consistency with the valve requirements;

5. When installing the valve, the user must reserve the necessary space for the valve drive;

6. The wiring of the drive device must be carried out according to the wiring diagram;

7. The gate valve must be maintained regularly, and no collision or squeeze is allowed to avoid affecting the seal.

Newsway Valves Materials

NSW valve body and trim material can be offered in Forged type and Casting type. Next to stainless and carbon steel material, we also manufacture valves in special materials such as titanium, nickel alloys, HASTELLOY®*, INCOLOY®, MONEL®, Alloy 20, super-duplex, corrosion resistant alloys and urea grade materials.

Available materials