Flat gate valve use structure description features

The use of slab gate valve: slab gate valve is suitable for natural gas, petroleum, chemical, environmental protection, urban pipelines, gas pipelines and other transportation pipelines, venting systems and steam storage devices, used as opening and closing equipment. The Z43 type single-plate slab gate valve with diversion holes is suitable for long-distance pipelines for natural gas extraction and purification.

Structure description of slab gate valve
1. The valve body has two forms. Generally, the nominal pressure is ≤2.5MPa, or ≤300Lb is the cast flat structure. When it is >2.5MPa or >300Lb, the cast circular structure is used.
2. The valve seat is a rigid floating valve seat with PTFE or PTFE sealing ring. It has a double sealing effect. The valve seat is tightened by the end â—‹ ring, and the piston is applied to the inlet and outlet by the piston effect of the floating valve seat. The double sealing structure completely separates the cavity in the valve body from the passage, and can repair the valve under working condition to eliminate the residue in the body cavity.
3. The ram is a rectangular parallel plate, which has a through hole with the same diameter as the channel (with a diversion hole), or a hole (with no diversion hole). When the slab is fully open, the channel is smooth and straight. The flow resistance coefficient is low and the pressure loss is small. When the shutter and the valve seat are always in contact with each other when opening and closing, the particulate dirt adhering between the sealing pairs can be wiped, and the sealing surface can be protected without being directly washed by the medium.

Features of the slab gate valve:
1. The sealing structure of the valve seat should be a structure with elastic pre-tightening force and simultaneous sealing of the upper and lower sealing seats. The seat and seal are always face to face sealed.
2. The seat has a self-cleaning function and is not directly flushed by the airflow during the opening or closing of the valve. The seat should be made of a lubricated, non-abrasive material.
3. The failure of the valve actuator will not affect the rest of the valve . Repair and replacement work can be carried out without removing the valve.
(1) Yoke bushing – The aluminum bronze yoke bushing is equipped with a needle thrust bearing, which greatly reduces the operating torque.
(2) Stem – thread length up to bracket; pin and spot weld; stable.
(3) Pressure Seal – Simple construction with segmented retaining ring and silver-plated mild steel washers to help disassemble and achieve a good bonnet seal.
(4) Seat Ring – The welded seat ring is perpendicular to the flow path for easy maintenance.
(5) Actuators – These valves can be equipped with electric, hydraulic or pneumatic actuators. The standard manual handwheel is configured below DN300, and the helical gear operating mechanism is configured above DN350.
(6) Yokes – Fully assembled yokes are seismically tested for easy maintenance and installation of actuators.
(7) Gland – two-piece, self-adjusting gland to avoid being ejected.
(8) The overall rear seat – hard surface, long service life.
(9) Disc – The spring-loaded flap is self-adjusting, reducing the torque requirements of the actuator.
(10) Integral stop – The integral cast bracket stop, positioning the assembled bracket flap makes the seat more stable and reliable.

The valve body has both cast and welded construction.
The valve seat adopts O-ring sealing and pre-tightening floating valve seat structure to make the valve inlet and outlet bidirectionally sealed; and the opening and closing torque of the structure is only 1/2 of the ordinary valve, which can easily open and close the valve.
The metal-to-metal sealed valve has a grease-injecting structure on the outside of the valve body. The grease enters the valve sealing surface through the grease injector and the valve seat, so that the valve reaches zero leakage.
The valve seat is inlaid with PTFE on the sealing surface, and has a double sealing of PTFE to metal and metal to metal, and the PTFE sealing surface simultaneously removes the dirt of the gate.
The gate and valve seat are treated by special process, spray-welded hard alloy, wear-resistant PTFE, and achieve double sealing. It can be double-protected with grease-assisted sealing, which is more reliable and has a longer service life.
The ram with the diverter valve , whether fully open or fully closed, always conforms to the sealing surface, and the sealing surface is protected from direct scouring of the medium, thus prolonging the service life.
When the valve is fully open, the channel is smooth and straight, the flow resistance coefficient is very small, no pressure loss, and the pipeline can be cleaned by the ball.
The slab gate valve adopts the packing structure with self-sealing ability, no need to adjust frequently, the opening and closing is extremely light, and the sealing is reliable. The packing letter is provided with auxiliary sealing grease injection structure, the sealing performance is absolutely reliable, and the zero leakage is truly achieved; The valve packing is easy to leak out.
When the valve is closed, the internal cavity high pressure can be automatically removed (see the working principle diagram for details) to ensure safe use.
Fully enclosed structure, good protection performance, can meet the requirements of all weather.
The valve is provided with an indicator rod or an observation window to indicate the opening and closing of the valve.