DN1200 Double Offset Butterfly Valve Introduction

Butterfly valve is a commonly used industrial valve that utilizes a rotating butterfly plate to control the flow in a pipeline.There are various types of butterfly valves, which can be categorized into centerline, single offset, double offset, and triple offset. In this paper, we will focus on DN1200 double offset butterfly valve, which is a high-performance butterfly valve with many advantages and suitable for various working conditions.

What does DN1200 mean?

DN is an abbreviation for nominal diameter, which indicates the standard size of a pipe or valve.DN1200 indicates a nominal diameter of 1200 mm, i.e. 1.2 m. A DN1200 (48 inch) double eccentric butterfly valve is a double offset butterfly valve that is suitable for piping or equipment up to DN1200.

What is the difference between double offset butterfly valve and centerline butterfly valve?

Centerline butterfly valve is the simplest and most common type of butterfly valve, its structure is characterized by the rotary center of the butterfly plate, the axis of the valve stem and the center of the valve body in the same position. This structure makes the centerline butterfly valve easy to manufacture, but it also brings some disadvantages:

• The butterfly plate and valve seat are always in the state of extrusion and scraping, resulting in high opening resistance, poor sealing performance and fast wear.
• The valve seat is generally made of elastic materials such as rubber or PTFE, so it is limited by temperature and pressure, and cannot be used in high temperature and high pressure environments.
• When the valve is closed, the sealing principle is positional sealing, i.e., it relies on the butterfly plate to squeeze the valve seat to produce sealing effect, so it has high requirements on the closing position, low pressure-bearing capacity, and can only realize one-way sealing.

Double offset butterfly valve is a high-performance butterfly valve further improved on the basis of single offset butterfly valve. Its structural feature is that the axis of the valve stem deviates from both the center of the butterfly plate (first offset) and the center of the valve body (second offset). This makes the double offset butterfly valve have the following advantages:

• The butterfly plate quickly disengages from the valve seat after opening, substantially eliminating friction and wear between the butterfly plate and the valve seat, and improving the life of the valve seat.
• The valve seat can adopt soft seal or metal seal, which is suitable for high temperature and high pressure environment.
• When the valve is closed, the sealing principle is torsional sealing, i.e., it relies on the contact surface pressure of the valve seat to produce the sealing effect, so it does not depend on the closing position, has high pressure-bearing capacity, and can realize two-way sealing.

Why choose Double Offset Butterfly Valves?

The Double Offset Butterfly Valve is a high performance butterfly valve that offers the following advantages, making it ideal for many industrial applications:

• Provides high capacity and minimal flow restriction for draining and regulating systems such as water plants, power plants, steel mills, etc.
• Saves installation space and cost and is lighter and more compact than other types of valves.
• Provides good sealing performance and leakage for applications requiring tight fluid control.
• Provide flexible control range and precise flow regulation, suitable for occasions where precise flow control is required.

VALTECCN is a professional butterfly valve supplier and manufacturer with many years of experience in designing, producing and selling butterfly valves.VALTECCN can provide double eccentric butterfly valves of various types, specifications, materials and pressure ratings to meet the needs of different customers.
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