How to choose a suitable butterfly valve? The size of the butterfly valve is an essential parameter. To measure correctly the bf valve, it’s necessary to know the structure and the components of the butterfly valve.
1. What are the components of the butterfly valve?
In summary, the bf valve is composed of four parts: body, disc, stem and seat.
Butterfly Valve body: the valve body refers to the major part of the bf valve, which is placed between two pipes; the face-to-face dimension refers to the distance between the two ends of the bf valve.
Butterfly Valve Disc: the disc refers to the rotating plate inside the valve, which shuts off or regulates the flow.
Butterfly Valve Seat: the butterfly valve seat refers to the interference fit between the disc edge and the inner surface of the body; this butterfly valve seat can be metal with good mechanical properties, or soft material offering a better sealing effect.
Butterfly Valve Stem: The butterfly valve stem refers to the shaft that connects the disc with the actuator; the stem of the butterfly valve can be a one-piece shaft or a two-piece shaft design.
2. How to measure a butterfly valve?
Technically speaking, there are three main parameters to measure the butterfly valve:
Face-to-face dimension: mainly the most popular standard is ASME.
Pressure rating: The most popular ASME pressure classes are Class 150, 300, and 600; the butterfly valve can allow up to 1500 psi maximum pressure.
Valve size: This refers to the butterfly valve dimensions in mm. Generally speaking, it refers to the diameter of the valve that is equal to the nominal pipe diameter that connects to the valve. Generally, the butterfly valve size may range from 2 inches to 60 inches; but there are also those available up to 96 inches, depending on the manufacturer.
More specifically, the butterfly valve dimensions in mm are the following:
Length A – Length of butterfly valve body + stem endpoint.
Length B – Length from centerline x-axis to valve end
Length C – thickness of the valve body
Length F – length of the key
Length H – diameter of stem
Length J – Hole size
K – thread size
L – number of holes
P – diameter of circle from center of lug hole
Apart from the three main parameters mentioned above, the size of the valve seat is another crucial parameter, especially when there are needs to fix and replace butterfly valve seats. In order to purchase the bf valve seat of the right size, it’s essential to know the following parameters of the bf valve seat:
HS – Diameter of Side Bore, mm
TH – Height of Seat, mm
CS – Thickness of Seat, mm
ID – Internal Diameter of seat, mm
OD – Outer Diameter of seat, mm
Lituo offers a great variety of butterfly valves. And among them, the wafer butterfly valve and the flange butterfly valve are our star products. For your inquiry, we also offer the butterfly valve dimensions in mm. For more details, please click: