• The swing check valve functions by allowing flow forces to move the disc from the closed position to the fully open position in a sweeping arc motion against the hinge stop inside of the valve body.
• Due to the weight and center of gravity location of the disc and swing arm assembly, the valve will return to the closed position when the flow become interrupted or reversed.
• External counterweights mounted on the hinge pin are sometimes used to increase or decrease the reaction time and speed of the disc returning to the closed position.
• Swing check valves have no requirement for operators, and so the valve is operated automatically by flow reversal.
• The flow direction of the fluid is indicated by the arrow on the swing check valve body.

APPLICATION

• A swing check valve is recommended for use in systems consisting of gate valves because of the low pressure drop across the valve.
• Swing check valve also recommended for systems having low velocity flow and should not be used on systems with pulsating flow when the continuous flapping or pounding would damage the seat.

YDRAULIC DAMPERS

KEY FEATURES

• Special design of the hydraulic chamber cavities allowing easy and efficient drainage of hydraulic fluid from one chamber to the other through an interconnecting manifold which has an incorporated flow regulator allowing for fine throttling and different speed settings across the valves stroke.
• Several models available to cover all swing check valves and eccentric butterfly valves without dimensions or torques limitations.

Following available options:

• Speed control device which allow the adjustment of the operating time in two sequential steps, faster for the first part of the stroke and slower for the last segment.
• For butterfly valves it is possible to fit the damper with an eccentric counterweight allowing to reach the complete closure of the terminal part.
• Compact solution consisting of a fully enclosed cylindrical rotational device, consequently ideally suited for heavy duty operation which allows our clients long maintenance free periods due to non-exposed rotating components.

SWING CHECK VALVES

In swing check valves, the disc swings on a hinge onto the seat to block reverse flow, or off the seat to allow forward flow.

The seat opening cross-section is perpendicular to the centerline between the two ports.

CHARACTERISTICS

Forged of cast carbon, alloy and stainless steel, bolted joint between cap and body, renewable or welded seats.

PRESSURE SEAL BONNET

Swing check valves are available assembled with bolted bonnet or with pressure seal bonnet, that allows high pressure service. The main feature about the pressure seal bonnet is that the body-bonnet joints seals improves as the internal pressure in the valve increases, compared to other constructions where the increase in internal pressure tends to create leaks in the body-bonnet joint.

Internal pressure forces the bonnet upwards against the gasket, creating forces in the contact areas between the gasket and the bonnet. As pressure increases, leaks probability decreases, because of the tightening of the contact surface between the gasket and the body. The area where the body is in contact with the joint is covered by stainless steel, improving surface’s quality and avoiding corrosion issues.