What are the main standards for Butterfly Valve？

A butterfly valve is a quarter-turn rotary motion valve used to stop, regulate, and start flow. Butterfly valves are easy to open quickly. The 90-degree rotation of the handle provides full closure or opening of the valve. Large butterfly valves are usually equipped with a so-called gearbox, where the handwheel is connected to the valve stem via a gear. This simplifies the operation of the valve, but at the cost of speed.This article is about the standards and specifications of butterfly valve.

The following knowledge points are listed below:

• What is butterfly valve

• The standards of butterfly valve

• The applications of butterfly valve

1.What is butterfly valve

Butterfly valve is an improved valve that can be used to control liquid, gas or particles, viscous fluid, simple structure, easy storage and compact. This type of valve can control the fluid more economically and achieve zero sealing. Butterfly valves are classified as "right angle rotary" valves.

The metal flap is part of the valve design and opens or closes when it turns a quarter turn. The flap is called "Butterfly" connected to a stick. When the butterfly valve opens, the flap rotates (1/4 turn), allowing the liquid to pass through almost indefinitely. You can slowly open the valve to reduce the flow rate. By turning the throttle Valve (valve) to close the valve and prevent the passage of liquid.

This is due to the fact that the valve flap is always perpendicular or parallel to the fluid, regardless of its position, causing a pressure drop. Lug type butterfly valve: The structure of the lug type butterfly valve is similar to the three-piece ball valve. Because one end of the wire can be removed without producing an effect on the other end. This can be achieved with studs and flanges, because each flange has its own bolt. The most important advantage of these butterfly valves is that this means that you do not need to shut down the entire system to clean, inspect, repair or replace the valve.

Lamellar butterfly valve: The role of the lamellar butterfly valve is to seal the bidirectional pressure difference in fluid flow. In other words, in order to avoid any backflow in the unidirectional flow system, the silicon wafer type butterfly valve is designed to prevent tight sealing and bidirectional pressure difference. This is achieved by precision machining flat flange surfaces and tightly sealing gaskets and precision discs in gaskets.

2. The standards of butterfly valve

All butterfly valves comply with API-609, MSS SP-67 and ISO 5752 face-to-face dimensions. The diameter of the butterfly valve is between 2 and 12 inches, suitable for the occasion of 250psi/WOG; the diameter of the valve is more than 14 inches, suitable for the occasion of 200psi/WOG. In end applications, all butterfly valves are fully rated. All butterfly valve bodies are made of ductile iron 65-45-12. Two-way test, good air tightness, zero leakage. The lug body is fully rated and suitable for ASME Class 125 and Class 150 flanges. The disc type valve body is suitable for ASME 125, ASME 150, JIS, DIN or B.S. flanges. The secondary seal is automatically adjusted. All elastomers and all internal bearings are non-corrosive and non-metallic. The EPDM rubber seat is suitable for sustained high temperatures of 250 degrees Fahrenheit and can reach 2000 ppm in chlorinated applications.

3. The applications of butterfly valve

The typical applications are:

• On/off isolation

• Terminal maintenance/clearance of downstream pipelines

• Heating, ventilation and air conditioning systems

• Industrial process piping

• City water intake

• Municipal chlorinated water system (2000ppm)

• Municipal water supply and reservoir

• Throttling and process control

• Full vacuum

• Aeration and blower installation

Now i would assume that you know about the butterfly valves standards.