Do you know how to maintain the ball valve?

Do you know how to maintain the ball valve?

Maintenance of ball valves.

The ball valve remains under pressure fluid inside the valve body in the closed position

Prior to repair.

① release the line pressure and keep the valve in the open position; disconnect the power or gas source; disconnect the actuator from the bracket

Must first identify the ball valve upstream and downstream pipeline has been removed from the pressure, before disassembly decomposition operation

② decomposition and reassembly must be careful to prevent damage to the sealing surface of the parts, especially non-metallic parts, take out the O-ring should use special tools

③ assembly flange bolts must be symmetrically, gradually and evenly tightened

④ cleaning agent should be compatible with the rubber parts, plastic parts, metal parts and working medium (such as gas) in the ball valve.

⑤ non-metallic parts should be immediately removed from the cleaning agent after cleaning, shall not be immersed for a long time

⑥After cleaning to be washed wall cleaning agent evaporates (available not dipped in cleaning agent silk cloth wipe) for assembly, but shall not be set aside for a long time, otherwise it will rust, contaminated by dust

(7) new parts in the assembly before the need to clean

⑧ assembly should not allow metal debris, fibers, grease (except for the use of provisions) dust and other impurities, foreign objects, such as pollution, adhesion or stay on the surface of the parts or into the cavity, if there is a micro-drain at the packing, must then lock the stem nut.

Note: Do not lock too tight, usually lock again 1/4 turn ~ 1 turn, the leakage will stop.

A) Disassembly

① Make the valve in half-open position, flush and remove any possible hazardous substances inside and outside the valve body.

②Close the ball valve, remove the connecting bolts and nuts on both flanges, and then remove the valve completely from the pipeline.

③Remove the actuator-actuator, connecting bracket, lock washer, stem nut, butterfly shrapnel, Gnan, wear plate, and stem packing in order.

④Remove the body cover connecting bolt and nut, separate the valve cover from the body, and take off the valve cover gasket.

⑤ Make sure the valve ball is in the "off" position, which can be easily taken out of the valve body, and then remove the valve seat.

⑥Gently push the stem down from the body center hole until it is completely removed, then remove the O-ring and stem packing.

Note: Please operate with caution to avoid abrasion of the stem surface and the body stuffing box sealing area.

B) Reassembly

① Clean and inspect the disassembled parts, and it is highly recommended to replace its seals such as seat and bonnet gasket with spare parts kits.

②Assemble in the reverse order of disassembly.

③Use the specified torque to cross-lock the flange connection bolts.

④Lock the valve stem nut with the specified torque.

⑤After installing the actuator, input the corresponding signal to rotate the spool by rotating the stem to bring the valve to the open and closed positions.

⑥If possible, please conduct pressure seal test and performance test on the valve according to the relevant standards before back-installing the pipeline.

 

1、Principle

The opening and closing part of the ball valve is a sphere, and the sphere rotates around the center line of the valve body to open and close the valve.

 

2、Applicable places

Low pressure, small diameter pipeline used to cut off the flow of water and change the distribution of water or need to quickly open and close the place.

 

3、Characteristics

①Low flow resistance.

②Simple structure.

③Small volume and light weight.

④The sealing surface of the ball valve is made of plastic and has good sealing properties.

⑤easy to maintain, the seal is generally movable, easy to disassemble and replace.

⑥ fully open or fully closed, the sealing surface of the ball and seat is isolated from the medium, the medium through will not cause erosion of the valve sealing surface.

 

4、Classification

(1), commonly used ball valves are divided into floating ball valves, fixed ball valves, lift lever ball valves, etc. according to their operating principles.

(2), ball valves can be divided into straight-through, three-way and right-angle according to their channel position.

 

5、Construction and installation points

(1), installation location, height, import and export direction must meet the design requirements, the connection should be solid and tight.

(2), all types of manual valves installed in the insulation pipeline, the handle shall not be down.

(3), the valve must be installed before the appearance of inspection, the valve nameplate should comply with the current national standard "General Valve Marking" GB 12220 provisions. For working pressure greater than 1.0 MPa and in the main pipe to play a cutting role in the valve, the strength and tightness test should be conducted before installation, after passing before use. Strength test, the test pressure for the nominal pressure of 1.5 times the duration of not less than 5min, the valve shell, packing should be no leakage for qualified. Tightness test, the test pressure is 1.1 times the nominal pressure; test pressure in the test duration should be in line with the GB 50243 standard requirements, to the valve sealing surface no leakage as qualified.

(4), the valve flange and pipeline flange between the pipeline design requirements to install the gasket.

(5), with the drive mechanism of the ball valve, installed in accordance with the provisions of the product instruction manual.

Cautions.

(1) must first identify the ball valve upstream and downstream pipeline has been removed from the pressure, before disassembly decomposition operation.

(2) non-metallic parts should be removed from the cleaning agent immediately after cleaning, not long soaking.

(3) assembly flange bolts must be symmetrical, gradually and evenly tightened.

(4) cleaning agent should be compatible with the rubber parts, plastic parts, metal parts and working medium (such as gas) in the ball valve. When the working medium is gas, gasoline (GB484-89) can be used to clean metal parts. Non-metal parts with pure water or alcohol cleaning.

(5) decomposition down each single ball valve parts can be cleaned by immersion. Still have not decomposed down the metal parts of the non-metal parts can be used clean fine impregnated with cleaning agent silk cloth (to avoid fiber off adhering to the parts) scrubbing. Cleaning must remove all adhering to the wall of grease, dirt, accumulated glue, dust, etc.

(6) ball valve decomposition and reassembly must be careful to prevent damage to the sealing surface of the parts, especially non-metallic parts, take out the O-ring should use special tools.

(7) cleaning to be washed after the wall cleaning agent evaporates (available not soaked cleaning agent silk cloth wipe) for assembly, but shall not be set aside for a long time, otherwise it will rust, contaminated by dust.

(8) new parts in the assembly before the need to clean.

(9) use grease lubrication. Grease should be compatible with the ball valve metal materials, rubber parts, plastic parts and working medium are compatible. When the working medium is gas, use for example, special 221 grease. Apply a thin layer of grease on the surface of the seal mounting groove, a thin layer of grease on the rubber seal, the sealing surface of the valve stem and a thin layer of grease on the friction surface.

(10) assembly should not allow metal debris, fibers, grease (except those specified for use) dust and other impurities, foreign objects and other contamination, adhesion or stay on the surface of the parts or into the inner cavity.

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