BTL BUTTERFLY CHECK VALVE (DUAL PLATE) – MODEL: H76X

The BTL butterfly check valve, Model H76X, is a device that allows fluid to flow in one direction only and prevents backflow, protecting pumps and other equipment in the system from pressure drops and water hammer. With a slim, lightweight wafer-type design and two discs that operate independently with the assistance of return springs, this valve offers an optimal solution in terms of space and installation cost for projects and buildings.

Butterfly check valves are commonly used in water supply and drainage, wastewater treatment, HVAC, fire protection, and industrial projects.

Technical information on the BTL H76X butterfly check valve

The butterfly check valve is a wafer-type check valve with spring-return flip discs. Its construction is fairly simple, consisting of 5 main component groups:

Detailed construction table

Dimension table of the BTL butterfly check valve, Model H76X

The table below gives detailed dimensions of the H76X butterfly check valve: diameter D; bolt circle D1; opening clearance D2; body length L; radius R; and thickness T:

Advantages and disadvantages of the BTL H76X butterfly check valve

Advantages

• The wafer design has no flanges of its own. The valve body is clamped directly between two pipeline flanges using through-bolts. As a result, the amount of material used for the body of the BTL butterfly check valve is significantly lower than for a standard flanged valve, leading to lower production costs and a lower price.
• The face-to-face length is much shorter than a flanged valve of the same diameter, making it suitable for systems with limited space such as pump rooms, technical shafts, or pipelines running under floors.
• Installation and maintenance are faster, because only one set of through-bolts is needed, instead of tightening each of the valve’s flanges separately.
• Its light weight reduces the load on pipe supports and hangers, and makes handling convenient for small and medium sizes.
• It can be installed both horizontally and vertically (with upward flow), because the closing mechanism relies on a spring rather than on gravity as a swing check valve does. This gives more flexibility when designing pipelines with vertical sections.

Disadvantages

• The BTL butterfly check valve cannot stand alone on the pipeline; it must be clamped between two flanges. So when one side of the pipeline needs maintenance, the entire related system usually has to be drained.
• Size and pressure range are limited. This valve type is common in the PN10 and PN16 range and in small to medium sizes, and is rarely used for large diameters or high pressures, because the clamping force of the through-bolts makes it difficult to ensure even sealing around the whole circumference as the size increases.
• It requires high precision when aligning the two flanges during installation. Any misalignment directly affects the tightness of the sealing ring.

Installation locations and applications of the BTL butterfly check valve, Model H76X

After the pump, to prevent backflow when the pump stops

This is the most common installation location for the butterfly check valve. While the pump is running, the flow pressure is high enough to overcome the spring force, and the discs open to let the fluid pass normally. When the pump stops suddenly, the pressure head in the pipeline downstream of the pump tends to push the fluid back toward the pump. Without a check valve, this reverse flow can make the pump spin backward, damaging the pump shaft, bearings, or seals. Thanks to the spring-return mechanism, the discs close almost immediately when the forward pressure is lost, which limits the hydraulic shock caused by slow closing.

On water supply system pipelines

In domestic or industrial water supply systems, the BTL butterfly check valve is often installed at locations where a fixed flow direction must be maintained. Examples include after a booster pump station, before a storage tank, or at junctions between multiple supply sources, to prevent water flowing backward and causing cross-contamination between lines.

In fire protection systems

Fire protection systems require stable pressure and flow when a fire occurs. The butterfly check valve is installed on main pipelines, especially at the discharge of the fire pump, to ensure water does not flow back toward the pump or between branch lines when the system operates multiple fire-fighting points at the same time.

Piping systems that require fast closing

Because it closes by spring force rather than gravity, the butterfly check valve is suitable for systems that require instant closing when the flow stops or reverses. This minimizes hydraulic shock and protects other equipment in the system, such as pumps, flow meters, or upstream control valves.

An Phu Thanh is the official distributor of the BTL butterfly check valve, Model H76X, in the full size range, with transparent CO and CQ documentation. If you need consultation and a detailed quotation, please contact us directly via Hotline/Zalo: 0946 729 913. Our experienced team will respond to you promptly.