SK735X Surge Anticipating Valve is a diaphragm type of hydraulic control valve driven by the hydraulic pressure within the piping system. The valve dissipates surges caused by power failure to pumps. The valve anticipates the surge by opening on low line pressure associated with sudden stopping of pumps. This assures that the valve is open when the return high pressure surge arrives.

Pressure from the header is directed to the bonnet of the Closing Speed Control, keeping the main valve closed if there is no flow through the two pilot valves. When one of the pilot valves opens and there is more flow out of the bonnet than is coming in, the main valve opens.

◔Operational principle

The valve is closed when the line pressure is between the set points of the two pilots. The valve opens when the line pressure drops below the setting of Low Surge Pilot. The valve also opens when the line pressure exceeds the setting of High Surge Pilot.

Main Valve is normally open when pressure is applied to the valve inlet. When this same pressure is applied ipating Valve.

to the bonnet, the Main Valve closes tight because the area of the diaphragm is greater than the area of the seat. Pressure above the diaphragm determines the position of the Main Valve.

Bonnet pressure is controlled with a pilot circuit consisting primarily of the following items:

1.A pilot line from the header to the bonnet including parts composed of Strainer etc.

2.Two pilot lines from the Main Valve bonnet through the outlet of the Main Valve.
Pressure from the header is directed to the bonnet of the Closing Speed Control, keeping the main valve closed if there is no flow through the two pilot valves. When one of the pilot valves opens and there is more flow out of the bonnet than is coming in, the main valve opens.
Pressure from the header is directed to the bonnet of the Closing Speed Control, keeping the main valve closed if there is no flow through the two pilot valves. When one of the pilot valves opens and there is more flow out of the bonnet than is coming in, the main valve opens.

◔ Property and advantages

• Driven by pressure of pipe system, work automatically with energy of pipe system to achieve energy conservation and environment protection.

• Controlled by the pilot valve, lower energy consumption, achieve accurate pressure reducing results, have function of stabilizing pressure after the valve.

• Dual cavity design, with functions of fully opening and fully closing. Slow shut causes no pressure fluctuation, and the diaphragm with support is well protected.

• Have internal orifice, connect bottom cavity and outlet of the basic valve, make sure stability of reaction to keep stability of pressure after the valve, avoid any vibration and noise.

• Channel with straight-flow, slight friction loss, no eddy flow and turbulent flow, cut down the damage of cavitation.

• Long pitch orientation design for stem move, stable and no gap resistance.

• Balanced automatically, big gap design on connection of disc and stem, disc is free on the vertical flat against stem, it can balance the tolerance from machining and sealing surface. Good connection without leakage. Achieve functions of both reducing dynamic pressure and reducing static pressure.

• Ductile iron castings with nodularity higher than 90%, foundry in house with advanced melting technology and strict quality control system, testing reports and testing bars can be supplied with order. Records and testing bars maintained for one year in the factory.

• Good corrosion resistance, with stainless steel, copper alloy, rubber made from DuPont and other rust- resisting material, fusion bonded epoxy coating both for interior and exterior surface of the basic valve. All the characteristics in accordance with ANSI/AWWA C550 and other international specifications like WRAS, NSF61.

SK710X

Notes for installation and debugging

• All the Pressure Reducing Valves have been finished initial debugging tests before delivery. Further dubugging test is also suggested during using according to different working conditions. After the pipe system becomes stable, please loose the adjusting screw on the top of pilot valve to the top- most position.

• After the pipe system becomes stable, please loose the adjusting screw on the top of pilot valve to the top- most position.

• Tighten adjusting screw of pilot valve in clockwise slowly. When outlet pressure increase to the set pressure please fasten the locknut under the adjusting screw.

• If go beyond the set pressure during adjusting, please repeat the above steps. Remember, pressure can be only adjusting from low level to high level and pay attention to make the adjusting slowly.