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Gate Valve Installation & Maintenance Manual

- Feb 02, 2018 -

Gate Valve Installation & Maintenance Manual

- Xiamen Freet Fluid Control Co., Ltd.


²  Use and Main Performance Specifications

This gate valve is suitable for water, steam, oil and so forth medium pipeline for opening and closing with the working temperature ≤ 425 ℃.


²  Structure and Working Principle

1. The valve is the flanged connection, manufacturing implementation of GB / T 12234 standards, testing implementation of the EN 13927 standards. The valve mainly composed of the body, wedge disc, stem, bonnet, the electric actuator and other components.


2. It is mainly rotated by an electric actuator or hand wheel to make the valve stem up or down, so as to drive the wedge disc perpendicular to the fluid for linear displacement, to achieve the purpose of open and close.


3. Electric actuator with the limit switch, which can automatically cut off the circuit to the end. For safety reasons, the electric actuator simultaneously set the power overload protection device and signal indicator.


²  Storage, Installation, and Use of Precautions

1. This product should be stored in a dry warehouse, non-open warehouse.


2. Long-term storage, regular inspection. The surface should be cleaned once every 6 months, a rust inhibitor surface dirt.


3. The valve should be mounted on a horizontal pipe with the drive up and the valve stem perpendicular to the media pipe.


4. Installation should carefully and check the performance of the gate valve is in line with performance standards.


5. Valve does not allow to regulate flow.


6. After the valve is installed, it should be manually turned on to 20 ~ 50 degrees during commissioning. And you need to check if the direction of the valve rotation is consistent with that of valve opening. If not, the phase sequence must be changed.

After determining the direction, and then you adjust the full-on trip switch. Generally, the fully open/closed position and the torque switch has been adjusted before delivery and without adjustment on site.


7. Note the following when installing:

   ⑴ Clean the pipe, valve cavity, sealing surface and all the exposed surface of the transmission of dirt and sand before installation and be careful not to bump sealing surface.

   ⑵ Check whether the bolts around evenly tightened.

   ⑶ Installation to match the appropriate manual device.

   ⑷ Manual device and valve connection to be solid and reliable.

   ⑸ The installed manual device should make the product open and close freely.

   ⑹ Manual devices and valves should be lubricated at regular intervals. Do this once a month.

   ⑺ The guard should be added to the top of the manual device in case of the poor environment.

   ⑻ The lifting sling shall not be tied to the electrical actuator or stem, which should be placed in the waist of the valve.

   ⑼ After the valve is installed, it shall be tested according to the manual of the electrical actuator before it is officially put into operation.


8. After the gate valve is installed, it must be fully open during the pressure test.


9. During the operation, in case of an outage, you should firstly cut off the power, and then moving the wrench in accordance with the manual operation.


10. before the valve is running, Denso should be injected into the bottom of the root diameter of the valve stem oil.


11. Exposed parts of the stem and electrical transmission section, should be regularly coated with lubricating oil.


12. The valve should be checked regularly the following in use

   ⑴ the wear and tear condition of the sealing surface

   ⑵ the wear on the stem, stem nut, and trapezoid thread

   ⑶ if there is the dirt accumulation between the sealing surface of body  the wedge  

   ⑷ if the packing and gasket failure

13. The seal test is required after the valve is serviced


²  Malfunction and Elimination Methods

Possible   Failure

Reason   For The Failure

Troubleshooting   method

Packing Leakage

1. The packing cover is not compressed.

2. Insufficient packing.

3. Overfill packing failure.

1. Evenly compress the packing gland.

2. Add filler.

3. Replace the packing again.

Leakage of the sealing surface of the connecting flange

1. The flange connection bolts are not tightened.

2. The flange sealing surface is damaged.

3. The gasket rupture or failure.

1. Tighten the bolts evenly and symmetrically.

2. Re-repair flange sealing surface.

3. Change the gasket.

Seal Leakage

1. There is debris on the sealing surface.

2. Sealing surface damage

1. Clean the sealing surface.

2. Rework the sealing surface or replace the part.

Electric device turning is not flexible or the valve can't be opened and closed

1. The packing is pressed is too tight.

2. The packing gland fastening tilt.

3. There is the dirt inside the stem thread or thread damage. 4. The   stem deformation

5. The Transitional device is damaged.

1. Properly unscrew a little for the packing gland.

2. Calibration gland verticality.

3. Remove dirt or replace parts.

4. Replace the stem.

5. Replace the transition device.

The motor does not stop at the end of the open/close or the open/   close can't reach the end

1. Limit switch failure or overload protection devices are not accurate.

2. Limit switch moves too early or too late.

1. Change the limit switch or adjust the overload device.

2. Adjust the limit switch.