Types of Trunnion Mounted Ball Valves

Trunnion mounted ball valves are available in many different configurations. They are highly customizable so you can choose the size, type, and actuator that suits your needs. Here are some common types of trunnion ball valves.

Based on Body Configuration
Body configuration determines how a valve can be accessed for maintenance or repair. There are two types of trunnion mounted ball valves based on body configuration.

Top Entry Trunnion Mounted Ball Valve
For a top entry trunnion mounted ball Valve,the ball is installed from the top of the ball valve. This type of ball valve has a removable bonnet cover on the top of the valve. The internal parts of the valve can be easily accessed by removing the bonnet without removing the valve from the pipeline.  The feature reduces the maintenance costs.

top entry trunion mounted ball valve
top entry trunion mounted ball valve

Side Entry Trunnion Mounted Ball Valve
Side entry ball valves are also known as split body trunnion mounted ball valves. In these ball valves, the body is divided into two or three pieces that are bolted together like flanges. One piece of the body is always larger than the rest. The larger piece holds the ball as well as the stuffing that goes around the ball. These valves are easier to inspect and repair as the smaller piece can be removed to access the valve.

side entry trunnion ball valve
side entry trunnion ball valve

Based on Valve Bores
The bore of the valve is the hole that is found in the middle of the disk or ball. Trunnion mounted ball valves have two types based on bore size.

Full Bore Trunnion Mounted Ball Valves
In full bore valves, the size of the diameter of the bore matches that of the connected pipeline. When the valve is open, the medium can flow freely without restriction through the bore. They are used in applications where pigging is required.

Reduced Bore Trunnion Mounted Ball Valve
A half bore trunnion valve has a bore size that has smaller size (normally reduced bore trunnion ball valve the sizes are as per API 6D or customer specifications)than the diameter of the connected pipeline. The flow path of the medium is restricted which results in higher energy losses.

reduced bore trunnion ball valve

Based on Assembly
The body of the valve may have one, two, or three pieces connected together though welded joints. There are two types of trunnion mounted ball valves based on the number of pieces.

Two-Piece Trunnion Mounted Ball Valve
This valve features two pieces of housing that are connected to each other through threaded connections. It is easy to open up one piece of housing to access the valve for cleaning or repair. However, the valve has to be disengaged from the pipeline before the housing can be removed.

3 Piece Trunnion Mounted Ball Valve
Three-piece trunnion mounted ball valves go one step ahead of the two-piece design.

Based on The Connection Between The Body and Bonnet

Bolted Body Trunnion Ball Valve
The body and bonnet is connected by bolting. This style has the advantage of easy maintenance. The user is able to disassemble the valve by bolt to repair the valve when necessary.

Welded Body Trunnion Ball Valve
The body and body is connected by welding.  This style of connection avoid the risk of leakage from the joint between the body and bonnet.

Based on Valve Seat

Soft Seat Ball Valve
The soft seat ball valves are refer to ball valves with the soft seat, such as PTFE, RPTFE, NYLON, PEEK, PPL, Delrin etc. Soft seat is easier for sealing while suitable for common temperature, normally no more than 260 .

Metal Seated Trunnion Ball Valve
Metal Seated Trunnion Ball Valve is usually used for high temperature or fluid wit solids. The metal seat surface is ordinary adopted with Stellite or WC etc to enable the seat and ball surface hard enough to resist the high temperature or solids in fluid.

Based on Body Material

Carbon Steel Ball Valves
Carbon Steel Trunnion Ball Valves are with carbon steel body such as ASTM A216 WCB and ASTM A105.

Stainless Steel Trunnion Ball Valves
Stainless Steel Trunnion Ball Valves are with stainless steel body such as ASTM A351 CF8, CF8M, CF3, CF3M, A182 F304, F316, F304L, F316L etc.

Duplex Steel Ball Valves
Duplex Steel Trunnion Ball Valves are with duplex stainless steel body such as ASTM A995 4A, 5A, 6A, ASTM A182 F51, F60 etc.

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