Product Knowledge | Basic Information on JW-LOK Trunnion Ball Valves

Release date:

2026-05-20

Trunnion ball valves are a type of fixed-ball valve whose core principle relies on securing the ball via upper and lower trunnions (supporting shafts), ensuring stable positioning during rotation and preventing displacement caused by fluid pressure. This design is particularly well-suited for fluid control in high-pressure, large-diameter, or harsh operating conditions.

A trunnion ball valve is a type of… Fixed-ball ball valves operate on the principle of securing the ball via upper and lower trunnions (supporting shafts), ensuring its stability during rotation and preventing displacement caused by fluid pressure. This design is particularly well-suited for fluid control in high-pressure, large-diameter, or severe-service applications.

Trunnion ball valves, due to their With its stable structure, reliable sealing, and long service life, it has become one of the preferred solutions in industrial critical fluid control systems.

Working Principle of Trunnion Ball Valve

‌

01. Opening/Closing Trigger

External force drives the valve stem, which in turn moves the ball inside the valve body, thereby… 90-degree rotation (a core actuation mechanism that determines the valve’s open or closed state).

02. State Transition

Start the process: When the sphere rotates to align the through-hole completely with the valve’s flow passage, the medium flows smoothly through the valve body, achieving full open position.

Closing Process: When the sphere rotates to a position where its through‑hole is completely perpendicular to the valve’s flow passage, the sphere’s surface blocks the media flow path, thereby fully shutting off the medium and completing the full‑closed operation.

03. Structural support

During rotation and operation, the sphere is rigidly supported by both the upper valve stem and the lower trunnion, securely mounted within the valve body to prevent deformation caused by process fluid pressure. “Floating” to prevent pushing and pressing against the downstream valve seat.

04. Torque Optimization

The dual-support structure significantly reduces operating torque and minimizes resistance during opening and closing, ensuring smooth operation.

05. Sealing Assurance

The valve seat, designed with spring loading or pressure actuation, remains tightly engaged with the ball’s surface at all times, ensuring a reliable sealing interface.

Depending on the operating conditions (temperature, pressure, and medium corrosivity), select metal seals, graphite, or… O-rings, as sealing elements, are tailored to various operating conditions to ensure reliable sealing.

JW-LOK Product Specifications

JW-LOK’s BT and BHT series trunnion-mounted ball valves are designed to operate in either the fully open or fully closed position. Through optimized structural design and sealing materials, the BT and BHT series can also handle higher pressures, up to 690 bar (10,000 psig).

Trunnion ball valve BT Series

01. Product Features

Category	Product Feature Description
Performance	Operating temperature range: -18°C to 232°C (0°F to 450°F)
	Internal diameter: 4.8 mm (0.19 in)
	Fixed-ball design, supports bidirectional sealing.
	Low operating torque
	Spring‑loaded valve seat: Both high‑ and low‑pressure systems feature leak‑tight integrity, reducing seat wear caused by sudden pressure surges.
	Compact structure, designed for maximum flow rate.
Structure	Ear‑shaped spherical design prevents the ball from popping out.
	The valve seat features an automatic pre‑tightening sealing function.
	Adopts a stem structure with an anti‑flyout design.
	The handle indicates the direction of media flow.
	Precise handle positioning
	Supports 2-way or 3-way flow paths
Optional equipment	Optional pneumatic or electric actuators are available.
	Optional mounting panel
	The three-way valve imposes no restrictions on the inlet and outlet.
Test	Conduct a leak test using nitrogen or compressed air at the rated working pressure, ensuring no visible leaks are present. For pressures exceeding 6,000 psig, perform the test at 6,000 psig.
Special Applications	Customizable low-temperature application trunnion-mounted ball valve
	We can supply BT-series three-way ball valves suitable for “fast-fill” CNG refueling station applications.
	We can provide BT-series ball valves that have obtained ECE R110 certification.

02. Product Technical Specifications

Technical Specifications
Category	BT Series	BHT Series
Specifications and dimensions	6mm-12mm or 1/4''-1/2'' 3/8'' or 1/4 -1/2 1/8
Valve body material	316 stainless steel, WCB carbon steel, A105
Valve seat material	PTFE/PEEK/PCTFE	PEEK
Operating temperature	-54℃ to 232℃ (PTFE) -196℃ to 450℃ (metal seal)
Maximum working pressure	690 bar (10000 psig)
Port Type	Male/Female Double-Card Socket Connector Female threads (NPT, British tapered pipe threads, British straight pipe threads, metric threads) Male threads (NPT, British tapered pipe threads, British straight pipe threads, metric threads), etc.