SUN LODC-XDN exhaust valve from the USA is in stock.

Brand

SUN/USA

Application Areas

Chemical, Petroleum, Energy, Electrical, General

SUN air vent valves are used to remove air from systems to reduce starting power and accelerate pump start-up in neutral shut-off circuits.

1: Air venting and starting valves require a minimum flow rate of 4 gpm (15 L/min) and a system pressure of 80 psi (5.5 bar).

2: The valve will reopen when the system pressure drops below 25 psi (1.7 bar).

3: After air is vented, the closing time varies from approximately 12 seconds at 4 gpm (15 L/min) to approximately 0.5 seconds at 50 gpm (200 L/min).

4: Sun's floating design minimizes interference caused by excessive installation torque and machining errors in the bore.

Working Principle of SUN Air Vent Valve (USA)

When gas overflows from the system, it rises along the pipes and accumulates at the highest point. Air vent valves are typically installed at this highest point. When gas enters the valve chamber and accumulates at the top, the pressure increases. When the gas pressure exceeds the system pressure, the water level in the chamber drops, causing the float to descend and open the vent. After the gas is expelled, the water level rises, and the float rises, closing the vent. Similarly, when negative pressure occurs in the system, the water level in the valve chamber drops, and the vent opens. Since the external atmospheric pressure is higher than the system pressure, atmospheric air enters the system through the vent, preventing the harmful effects of negative pressure. Tightening the valve cap on the valve body stops the vent. Normally, the valve cap should be in the open position. Air vent valves can also be used with isolation valves for easier maintenance.

Features of SUN Air Vent Valve (USA):

1. The float of the air vent valve is made of low-density PPR and composite materials, which will not deform even after prolonged immersion in high-temperature water. 1. It will not cause difficulty in the movement of the pontoon.

2. The pontoon lever is made of rigid plastic, and the connections between the lever and the pontoon and support are all movable connections. Therefore, it will not rust during long-term operation, preventing system malfunction and leakage.

3. The sealing end face of the lever is spring-supported, which can expand and contract accordingly with the movement of the lever, ensuring a tight seal when no air is released.

Installation: When installing the air release valve, it is best to install it together with the isolation valve. This ensures that the system remains sealed and water does not leak out when the air release valve needs to be removed for maintenance. It is made of low-density PP material, which will not deform even after prolonged immersion in high-temperature water.

Operating Instructions for SUN Air Vent Valve (USA):

When water begins to flow into the pipe, the plug remains in the open position to allow for significant air release. Once all air is released, water accumulates inside the valve, causing the float to rise and move the plug to the closed position, stopping the significant air release. When water is flowing normally through the pipe, if a small amount of air accumulates inside the valve to a certain extent, the water level drops, causing the float to descend as well. At this point, the air is released through the small orifice. When the pump stops, the water in the pipe dries up, or negative pressure is generated in the pipe, the plug quickly opens to draw in air, ensuring the pipeline is secure.

Technical Requirements for SUN Air Vent Valve (USA):

① Main Technical Parameters

a. Nominal pressure of the air vent valve: PN10.

b. Sealing test pressure: 1.1 MPa.

c. Strength test pressure: 1.5 MPa.

d. Water shut-off pressure of the air vent valve: ≤0.02 MPa.

e. Air shut-off pressure of the air vent valve: ≥0.07 MPa.

f. Pressure test shall comply with the provisions of standard GB/T13927. g. The connecting flange shall conform to the provisions of standard GB/T17241.6-98.

h. The maximum working pressure can reach 10 bar.

i. The maximum working temperature (water) is approximately 110℃.

② Performance Requirements

a. The air vent valve should have a large air venting capacity, enabling rapid air venting and restoration to normal water supply capacity in a very short time when the pipeline is filled with water from an empty pipe.

b. When negative pressure is generated in the pipe, the piston of the air vent valve should be able to open quickly and rapidly draw in a large amount of outside air to ensure that the pipeline is not damaged due to negative pressure. It should also be able to expel any small amount of air accumulated in the pipeline under working pressure.

c. The air vent valve should have a relatively high air closing pressure, with sufficient capacity to completely expel air from the pipeline in a short time before the piston closes, improving water delivery efficiency.

d. The water closing pressure of the air vent valve should not exceed 0.02 MPa, allowing the air vent valve to close under relatively low water pressure, thereby preventing a large outflow of water.

e. The air vent valve should use a stainless steel float (float) as the opening and closing element. f. The air vent valve body should be equipped with an anti-impact protective inner cylinder to prevent premature damage to the float (float) caused by the high-speed water flow directly impacting it after a large amount of air is released.

g. For air vent valves with DN≥100, a split structure should be adopted, consisting of a large air vent valve and an automatic air vent valve, to adapt to the pipeline pressure requirements. The automatic air vent valve should use a double lever mechanism to significantly amplify the buoyancy of the float, and with a low closing water level, impurities in the water are less likely to contact the sealing surface, preventing blockage of the air vent and greatly improving its anti-clogging performance. Simultaneously, under high pressure, the force amplification effect of the double lever allows the float to descend synchronously with the water level, preventing the opening and closing parts from being sucked in by high pressure like in traditional valves, thus ensuring normal air release.

h. For high flow rates, frequent pump starts, and DN≧100 diameter applications, a buffer plug valve should be installed on the air vent valve to mitigate water flow impact. The buffer plug valve should prevent large amounts of water spray without affecting large amounts of air release, ensuring that water delivery efficiency is not affected and effectively preventing water hammer. [1]

This type of unbalanced, pilot-operated shut-off logic valve is a 2-way switching unit and is in the closed state under spring bias. Pressure at port 1 or port 2 will counteract the spring force to open the valve, while pressure at port 3 will close it. The force generated at port 3 plus the spring force must be greater than the sum of the forces generated at ports 1 and 2 for the valve to remain closed. Note: The pilot area (port 3) is 1.8 times the working area of ​​port 1 and 2.25 times the working area of ​​port 2.

This type of valve has an effective seal between port 2 and the pilot port.

Because this type of valve is unbalanced, switching depends on pressure. The opening and closing of the cone valve core is the result of force balance in three regions: port 1 = 100%, port 2 = 80%, and pilot port = 180%.

This type of valve is affected by pressure at all ports; therefore, the operation of all aspects of the system over a complete cycle should be considered. Any change in pressure at any port may cause the valve to switch from the closed to the open position, and vice versa. All possible pressure variations in a complete hydraulic circuit must be considered to ensure the safety and reliability of the designed system.

Pilot port 3 requires controlled pressure. A blocked port 3 may result in pressure intensification due to the floating design of the sleeve.

All ports can accept pressures up to 5000 psi (350 bar).

Corrosion-resistant threaded cartridge valves are designed for use in corrosive environments and are identified by the suffix /AP in the valve model designation (see options below). The valve body is constructed of high-strength duplex stainless steel. Depending on the model, the adjusting bolt may be made of titanium alloy or silicon brass. The lock nut, locating thread, and various controls are made of 316 stainless steel. Internal parts are made of the same carbon steel lead alloy as standard valve components.

The Sun floating structure reduces the possibility of internal parts sticking due to excessive installation torque or machining errors in the socket/cartridge valve.