1. Main features of PE gas flat gate valve:

PE gas flat gate valve is a new generation product of gas specific valves, which is particularly suitable for direct burial use. The design of PE gas flat gate valve is unique. With a novel structure and excellent technical performance, it is mainly suitable for transporting and cutting off media on urban gas pipelines. It can be buried underground and directly connected to PE pipes without the need for steel plastic transition joints, reducing project costs. Only a small valve chamber needs to be built on the valve cover, which can be operated and maintained in all directions on the ground. It has good sealing performance, low flow resistance coefficient, easy operation and maintenance, and long service life. It is an ideal supporting product for natural gas, urban gas, liquefied gas and other pipelines.

2. Main parameters of PE gas flat gate valve:

model: PEZ67F

Caliber form: DN100~DN400

Pressure rating: PE connection (0.4MPa), valve body shell 1.6MPa

Connection form: welded end

Sealing form: Soft seal

Purpose: As of

Drive mode: Handwheel, spur gear

Flow direction: bidirectional

Temperature range:- 29℃~80℃

Valve body material: cast steel

Applicable media: natural gas, urban gas, etc

Design standards for PE gas flat gate valves: GB/T19672, CJ/T 3056-1995 General technical requirements for ductile iron and cast steel valves for urban gas use

PE gas flat gate valve flange standard: HG/T20592,GB/T9113

Structural length standard for PE gas flat gate valve: GB/T12221

Pressure testing standards for PE gas flat gate valves: GB/T13927, CJ/T 3055-1995 Testing and Inspection of Gas Valves

GB15558.1 Underground Polyethylene (PE) Pipeline Systems for Gas Use Part 1

Structural characteristics of PE gas flat gate valve products

1. Connection between PE gas flat gate valve and PE pipe: The two ends of the valve are PE pipes, which use the principle of steel plastic conversion joints and are integrated with the valve. In this way, it is directly connected to the PE pipeline with an electric melting sleeve, which is simple and convenient, greatly reducing the cost of using steel plastic conversion joints for steel valves.

2. Middle connection of PE gas flat gate valve (valve body and valve cover connection): The middle connection bolts are designed with countersunk holes to ensure no leakage and improve the anti-corrosion performance of the valve.

3. Sealing reliability of PE gas flat gate valve:

(1) Valve body and valve cover. The pressure bearing components such as gate plates are made of steel materials and will not deform due to changes in time and temperature, ensuring reliable sealing and avoiding the phenomenon of failure to open or close.

(2) The valve seat sealing surface is embedded with RPTFE, which has a soft and hard dual seal. During the opening and closing process, the parallel gate always matches the sealing surface of the valve seat, which can remove dirt on the gate and provide a more reliable seal.

(3) When the valve is fully open or fully closed, the sealing surface of the valve seat is not washed away by the medium, effectively protecting the sealing surface.

(4) The floating structure behind the valve seat has a rubber sealing ring or spring preload force, which allows the valve to seal even under very low pressure

4. Double isolation and isolation function: The valve is in the closed state, with both sides sealed, completely isolating the left and right media to achieve sealing, and the middle chamber has no pressure.

5. Elastic sealing: The valve seat is a floating double valve seat, and the outer circle adopts the principle of O-ring sealing piston effect. The elastic pre tightening force behind compensates for the sealing. The parallel gate only needs to be in contact with the sealing ring without additional force for sealing.

6. Removable valve seat: The valve seat is installed on the valve body with a floating structure, which can be disassembled and replaced online, and has bi-directional sealing.

7. Packing sealing: The valve cover packing box adopts a piston principle sealing sleeve O-ring and V-shaped pressure sealing structure, which does not require adjustment of opening and closing, is extremely lightweight, making the valve packing performance more reliable, solving the problem of the most easy leakage at the general valve packing, and the packing sealing structure makes its opening and closing torque much smaller than that of PE ball valves.

8. Release function: Release pipes can be installed on the left and right sides of the valve body, replacing the release pipes set in the pipeline and saving costs.

9. Closed indication: The fully enclosed opening and closing indicator needle can maintain a basic consistency with the degree of valve opening and closing, and enable the operator to clearly observe the valve opening and closing situation.

10. Anti corrosion measures: The exterior of the valve is coated with epoxy coal tar for anti-corrosion, which can have the same service life as the pipeline.

零件名称	零部件材料
	普通型		抗硫型
	GB/T    19672	API    6D	GB/T    19672	API    6D
阀门/阀盖	WCB	ASTM    A216 WCB	WCB	ASTM    A216 WCB
闸板	16Mn+ENP	ASTM    A515 GR70+ENP	1Cr18Ni9	304
阀杆	20Cr13	A276-420	1Cr18Ni9	304
阀座	A105+RPTFE	A105+RPTFE	F304+RPTFE	F304+RPTFE
填料	RPTFE/丁腈橡胶	RPTFE/氟橡胶	RPTFE/氟橡胶	RPTFE/氟橡胶
垫片	1Cr18Ni9+柔性石墨	304+柔性石墨	1Cr18Ni9+柔性石墨	304+柔性石墨
螺栓、螺帽	35CrMo、45	A193    B7、A194 2H	35CrMo、45	A193    B7、A194 2H
适用温度	-29～121℃	-29～121℃	-29～121℃	-29～121℃
适用介质	天然气，石油，水等	天然气，石油，水等	天然气，石油，水等	天然气，石油，水等

Outline drawing and dimensions of PE gas flat gate valve

• Dimensions
  

• 公称尺寸	D	D1	d	L	L1	H1	H2
  DN50	63	51.4		216	340	260	130
  DN65	75	61.4		241	340	360	160
  DN80	90	73.6		283	340	370	180
  DN100	110	90		305	350	410	214
  DN150	160	130.8		403	350	510	300
  DN200	200	163.6		419	350	580	388
  DN250	250	204.6		457	350	690	475
  DN300	315	257.8		502	350	760	547
  DN350	355	290.6		572	350	885	625
  DN400	400	327.2		610	350	1010	712
  DN450	450	368.2		660	350	1140	785
  DN500	500	409		711	350	1210	880

  
  

  
  

Storage, installation, use, and maintenance

1. Storage and Preservation

• A: Flat gate valves with diversion holes should be stored and transported in the fully open position (closed position without diversion holes), and should be neatly stored in a dry and ventilated warehouse. Stacking and outdoor storage are strictly prohibited. Both ends of the valve diameter must be blocked with protective covers to prevent impurities from entering the valve chamber and scratching the flange sealing surface or welding groove.

• B： Valves stored for a long time should be inspected regularly, and rust proof oil should be replaced regularly on exposed machined surfaces, and dirt and rust on the surface should be removed.

2. Installation

• A: Before installation, carefully read the user manual and verify whether the model, specifications, labeling, certificate of conformity, etc. match the on-site usage requirements.

• B： The flat gate valve with diversion holes should be in the fully open position (with no diversion holes in the closed position). Our company's valves allow fluid to flow in from either side. To ensure proper installation, the actual situation of pipeline transmission should be carried out according to the standard. Before installing the pipeline, the protective covers on the flanges at both ends should be removed.

• C： Use the corresponding specifications of seals and flange bolts, tighten the flange bolts in a diagonally staggered order, or follow the method recommended by the seal manufacturer.

• D： Before installing the welded valve, the rust proof oil and rust on the welding groove should be removed until the welding surface of the groove shows a metallic luster. Strictly weld by qualified welders according to the welding process specifications. After passing the inspection, anti-corrosion treatment shall be carried out on the weld seam.

• E： Before use, the pipeline and equipment of the valve should be purged and flushed to remove dirt, welding fluid, and other impurities from the pipeline and equipment, in order to avoid scratching the sealing surface (special reminder)

3. Use and maintenance

• After the valve is put into normal use, the following contents should be checked regularly.

• A: Check the sealing condition of the valve seat, gate sealing pair, valve stem packing, and valve body and valve cover connection parts.

• B： Check whether the manual or electric switch operation is flexible and reliable.

• C： Check if there is any accumulation of dirt in the valve chamber, and if so, it should be discharged from the bottom drain outlet of the valve body.

• D： Check if the bolt connections and valve accessories are loose, and tighten them if necessary.

• E： Check if the anti-corrosion paint on the surface of the valve has peeled off, and if so, touch up the paint in a timely manner.

• F： Valves that do not operate for a long time should be manually opened and closed at least once a year to maintain the flexibility and reliability of valve operation.

4. Operation of flat gate valve

• Rotate the handwheel clockwise to close the valve. Rotate the handwheel counterclockwise to open the valve.

• When the flat gate valve is opened or closed in place, the valve stem handle or handwheel should be rotated 1/2 turn. To ensure that the gate is in a floating state and maintain good sealing performance.

5. Possible faults and troubleshooting methods

故障现象	原因	排除方法
阀杆转动不灵	1.        填料压得过紧 2.        阀杆与其配合部位有损或　    积有污物 3.        开、关次数过多	1.        松动螺母重新调整 2.        拆开修整及清除污物
密封面有泄漏	1.        预紧力不够 2.        密封面有损或污物 3.        密封变形或失效	1.        增加预紧力 2.        清除污物 3.        重新修整或更换密封面
阀杆填料处渗漏	1.        填料压紧力不够 2.        填料使用过久失效	1.        重新调换螺母、螺栓 2.        更换填料
中法兰处渗漏	中法兰螺栓松动	重新均匀拧紧螺母




The main operational faults of flat gate valves are valve leakage and operational failures.

1. Valve leakage is divided into internal leakage and external leakage.

A: Internal leakage refers to the leakage of the valve seat and gate sealing pair, as well as the leakage at the joint surface between the valve seat and valve body.

B： External leakage refers to the leakage at the joint threads of the flange gasket, packing, and various connecting accessories (pressure relief valve, discharge valve, grease injection valve, etc.), and external leakage is not allowed.

2. Operation failure refers to the failure of the valve stem to operate flexibly and drive the actuator.

Precautions before disassembling the valve

1. Understand the properties of the medium inside the pipeline (pressure, temperature, toxicity, explosion-proof and other hazardous requirements).

Before removing the valve from the pipeline, close the shut-off valves at both ends of the valve to ensure that the pressure of the medium inside the valve and the connected pipeline has been completely discharged.

3. The valve should be in the half open position, and the discharge valve should be opened or blocked to discharge the medium and release the pressure of the medium in the middle chamber. The discharge of hazardous media should be directed to a safe location.




Note: Pre understand the detailed parameters, data, and prices of PE gas flat gate valves produced by Yongjia Zhili Valve,

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