Tag Archive for: dual check valve

VALVE:CHECK;STEEL,
300DIAX180MM L,
WAFER TYPE
QNSI SER#150 DBL
DISC 316+EPDM SEAT
APPLICATION:
POTABLE WATER
MFR: STV
CORPORATION OR
EQUIVALENT” NOTE:
SEAT MATERIAL: TO
BE
ADVISEDHS:848180409
0

The WAFER check valve refers to a valve that automatically opens and closes the valve flap by means of the flow of the medium itself, and is used to prevent the back flow of the medium, which is also called a check valve, a check valve, a reverse flow valve, and a back pressure valve. The check valve is an automatic valve whose main function is to prevent backflow of the medium, prevent the pump and drive motor from reversing, and discharge the container medium. The check valve can also be used to supply a line in which the pressure may rise to an auxiliary system that exceeds the system pressure. The check valve can be mainly divided into a swing type check valve (rotation according to the center of gravity) and a lift check valve (moving along the axis)

working principle
The function of this type of valve is to allow only the medium to flow in one direction and to prevent the flow in the opposite direction. Usually, the valve is automatically operated, and the valve flap is opened by the fluid pressure flowing in one direction; when the fluid flows in the opposite direction, the fluid pressure and the self-reclosing valve flap of the valve disc act on the valve seat to cut off the flow.
Among them, the stainless steel wafer type check valve belongs to this type of valve, and includes a swing type check valve and a lift check valve. The swing check valve has a hinge mechanism and a door-like flap that rests freely against the inclined seat surface. In order to ensure that the valve flap can reach the proper position of the valve seat surface each time, the valve flap is designed in the hinge mechanism, so that the valve flap has enough swinging space and the valve flap is truly and comprehensively in contact with the valve seat. The flaps can all be made of metal, or they can be inlaid with leather, rubber, or synthetic coverings depending on the performance requirements. With the swing-open check valve fully open, the fluid pressure is almost unimpeded, so the pressure drop across the valve is relatively small. The valve flap of the lift check valve is located on the valve seat sealing surface of the valve body. In addition to the flap being free to lift and lower, the valve is like a shut-off valve. The fluid pressure causes the flap to lift from the seat sealing surface. The backflow of the medium causes the flap to fall back onto the seat and shut off the flow. Depending on the conditions of use, the flap can be of all metal construction or it can be in the form of a rubber or rubber ring on the valve disc holder. Like the shut-off valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is limited. Very few].

Technical Parameters
Nominal pressure or pressure level: PN1.0-16.0MPa, ANSI CLASS 150-900, JIS10-20K
Nominal diameter or caliber: DN15～900, NPS 1/4～36
Connection method: flange, butt welding, thread, socket welding, etc.
Applicable temperature: -196 ° C ~ 540 ° C
Body material: WCB, ZG1Cr18Ni9Ti, ZG1Cr18Ni12Mo2Ti, CF8 (304), CF3 (304L), CF8M (316), CF3M (316L), Ti.
Different materials can be used for water, steam, oil, nitric acid, acetic acid, oxidizing medium, urea and other media.