Controlled Slow Closing Speed Butterfly Buffer Check Valve

The Controlled Slow Closing Speed Butterfly Buffer Check Valve from Dafugui is designed for municipal water transmission, industrial circulation systems, and pump station applications where uncontrolled valve closure may cause pressure fluctuations and mechanical stress.

The valve combines a butterfly check valve structure with an adjustable hydraulic buffer system. During normal operation, the disc opens with low flow resistance. When reverse flow occurs after pump shutdown, the hydraulic damping device controls the final closing stage, helping reduce sudden disc impact and minimize water hammer effects.

Manufactured with CNC-machined components, pressure-tested valve bodies, and multiple flange connection options, Dafugui valves are available for DN50–DN1400 pipeline systems with pressure ratings up to 2.5 MPa.

Adjustable Hydraulic Damping Control

Variable Hydraulic Throttle Adjustment

The Controlled Slow Closing Speed Butterfly Buffer Check Valve is equipped with an adjustable needle valve that controls oil flow resistance inside the damping chamber. By adjusting the throttle opening, maintenance engineers can modify the slow-closing speed according to actual pipeline requirements.

This allows the valve closing characteristics to be matched with different system conditions, including:

Long-distance water transmission pipelines

High-head pumping station

Large-diameter discharge lines

Industrial cooling water systems

Two-Stage Closing Performance

The valve adopts a two-stage closing process:

Fast Closing Stage (Initial Stroke)

The disc rapidly moves through the majority of its closing angle under reverse flow force, reducing the amount of reverse fluid movement.

Controlled Slow Closing Stage (Final Stroke)

As the disc approaches the seat position, the hydraulic cylinder gradually increases resistance, slowing the final movement and reducing mechanical impact on the valve seat.

This controlled closing sequence helps achieve smoother shutoff performance compared with conventional check valves without damping systems.

Hydraulic Buffer Protection

The Controlled Slow Closing Speed Butterfly Buffer Check Valve absorbs part of the disc closing energy through controlled oil displacement. This reduces:

Valve disc impact force

Pipeline vibration

Pressure fluctuation during pump trips

Mechanical stress on connected piping components

Technical Specifications

Quality Inspection & Factory Testing

To ensure reliable operation before shipment, Dafugui performs inspection procedures including:

Hydrostatic Pressure Testing

Valve bodies are tested under hydraulic pressure according to applicable standards to verify structural strength and sealing performance.

Hydraulic Cylinder Function Testing

Each damping assembly is checked for:

Smooth piston movement

Adjustable throttle response

Closing speed consistency

Dimensional Accuracy Inspection

Critical components including:

Shaft diameter

Disc alignment

Seat machining dimensions

Flange connection dimensions

are inspected using precision measuring equipment.

Coating Quality Inspection

Protective coating thickness and surface quality are inspected to improve corrosion resistance during long-term operation.

Frequently Asked Questions

How does the adjustable hydraulic cylinder control the valve closing speed?

The Controlled Slow Closing Speed Butterfly Buffer Check Valve controls closing speed by regulating oil flow through an adjustable throttle valve. Changing the throttle opening modifies the damping resistance, allowing engineers to adjust the final closing stage according to pipeline operating conditions.

Why is slow closing important in large water pipelines?

Large-diameter pipelines contain significant fluid momentum. Rapid valve closure can create pressure waves that stress pipes, joints, and equipment. Controlled slow closing helps reduce these sudden pressure changes during pump shutdown events.

Can Dafugui customize the valve according to different pump station conditions?

Yes. Dafugui can adjust hydraulic damping characteristics based on pipeline length, flow rate, pressure rating, and project requirements to provide a suitable valve configuration.

What inspections are performed before shipment?

Each valve undergoes pressure testing, dimensional inspection, hydraulic damping function checks, and coating quality inspection before delivery.