Common Failures and Installation of butterfly valves

The butterfly valve is also called a disc valve. It is a simple structured flow control valve that can be used for the switching control of low pressure pipeline media. Below we mainly introduce the structure and characteristics of stainless steel butterfly valve to help you deepen the understanding of the butterfly valve. 

Structure of butterfly valve

It is mainly composed of valve body, valve stem, disc and seal ring. The valve body is cylindrical, with short axial length and built-in disc. According to the structure, butterfly valves can be divided into offset plate type, vertical plate type, inclined plate type and lever type. 

Features of butterfly valve 

1. The butterfly valve has the characteristics of simple structure, small size, light weight, low material consumption, small installation size, fast switching, 90 ° reciprocating rotation, and small driving torque. It is used to cut off, connect and adjust the medium in the pipeline. It has good fluid control characteristics and closed sealing performance. 

2. The butterfly valve can transport the mud and minimize the accumulation of liquid at the pipe opening. It has good regulating performance and can achieve good sealing under low pressure. 

3. The streamlined design of the butterfly plate makes the fluid resistance loss less, which can be described as an energy-saving product.

4. The valve stem is a through-stem structure. After quenching and tempering, it has good comprehensive mechanical properties, corrosion resistance and abrasion resistance. When the butterfly valve is opened and closed, the valve stem only performs a rotary motion and does not perform a lifting operation.

The packing of the valve stem is not easy to break and the seal is reliable. It is fixed to the cone pin of the butterfly plate, and the outstretched end is designed to prevent punching out, so that the valve rod will not collapse when the valve rod and the butterfly plate are accidentally broken. 

5. Butterfly valve connection methods include welded.clamped,flange connection, threaded connection, and lug wafer connection.

The driving forms include handle level, electric, pneumatic actuated, which can realize remote control and automatic operation. 

Advantages of butterfly valves 

* Easy opening and closing, labor saving, small fluid resistance, and simple operation.

* Butterfly valve is simple in structure, small in size, short in structure length, small in size and light in weight, suitable for large-caliber valves.

* It can transport mud with minimal liquid accumulation at the mouth of the pipe. Good sealing at low pressures.

* When fully opened, the effective flow area of the valve seat channel is large, and the fluid resistance is small.

* The opening and closing torque is small, because the butterfly plates on both sides of the rotating shaft are basically equal to the action of the medium, and the direction of torque generation is opposite, so the opening and closing is labor-saving.

* The sealing materials of butterfly valve are generally EPDM,Silicone.Viton.Buna,PTFE, so the low-pressure sealing performance is good.

* The operation of butterfly valve is flexible and labor-saving, and manual, electric, pneumatic acuator with C-top can be selected. 

How to install butterfly valve, what are the precautions for daily maintenance? Follow us in the next article to get the answer.