Pneumatic pneumatic valve and pump sealing

pump and pneumatic valve effective seal depends on the parts of the overall situation, to pay special attention to, in the packing before installation, sure need to change the packing equipment has been isolated according to the field and system effectively. The following is used to guide maintenance personnel, engineers, and assembler correctly install and adjust the packing.
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when tools need to remove the old packing with new packing need to use special tools, as well as with a fastening device preloaded gland nut. In addition, the need to use the standard safety facilities often and comply with the relevant safety regulations.
before installation, the first to be familiar with the following equipment:
check packing ring cutting machine, calibration of torque spanner or wrench, helmet, calipers, fastening device of lubricants, both inside and outside mirrors, out packing, packing tool cutting, vernier caliper, etc.
. Clean and check the
1. Slowly loosen packing gland nut, releasing all of the residual stress inside packing components;
2. Move all the old packing, thoroughly clean the shaft/rod stuffing box;
3. Check the shaft/bar for corrosion, dents, scratches or excessive wear;
(4) to check whether there is burr, crack, other parts wear and tear, they will reduce the life of the packing;
5. Check the stuffing box if there is a big gap, and the eccentric degree of shaft/rod;
6. Replace any component which have larger defects;
7) check the old packing, as the basis of failure analysis, in order to find the cause premature failure of the packing.
　　. Measure and record
the diameter of the shaft/rod, gland aperture and depth, and when the water seal ring at that time, record the stuffing box at the bottom to the top of the distance.
　　. Choose packing
(1) to ensure that the selection of packing should meet the requirements of systems and equipment operating conditions;
(2) according to the measurement record, calculation of cross-sectional area of packing and the quantity of packing rings required;
3. Packing inspection, to ensure the zero defect;
4. Before installation, ensure the equipment and packing clean.
　　. Packing ring to
1) braided packing
on the appropriate size of the shaft winding packing, or the use of calibrated packing ring cutting machine; According to cleanly cutting packing into docking ( Square) Or miter ( - C) , at one time a ring and shaft or pneumatic valve rod inspection size are appropriate. Mould pressing and weaved

2. Make sure that the size of the ring and the shaft or pneumatic valve rod with precise, when necessary, according to the requirements of the packing manufacturers operating guidelines or cutting packing ring.
　　. Install packing
carefully every time you install a packing ring, each ring around the shaft or pneumatic valve stem, before installing the next ring should ensure that the ring have been completely in the stuffing box in place, the next ring should be staggered arrangement, at least degrees apart, general requirements. The most on a ring installed, tighten the nut by hand, gland evenly press. If there is a water seal ring, should check with the stuffing box at the top of the distance is correct. At the same time to ensure the shaft or pneumatic valve stem can free rotation.
　　. Adjust the packing
) Pump with packing
( ） Continue with the hand tighten gland nut;
　　（ ） Open pump, adjust gland nut, are allowed at this time a bit more leakage;
　　（ ） Slowly tighten gland nut, gradually reduce the leakage, leakage until achieve acceptable levels;
　　（ ） If sudden stop leak, should be back to twist the gland nut, to adjust to prevent packing overheating;
　　（ ） Adjust the leakage rate reached a stable state.
　　） Pneumatic valve with packing
consult packing manufacturer or enterprise's technical department regulations on torque or compression percentage, complete the following steps to tighten gland nut:
( ） Pressuring gland nut torque to the torque of the % or the compression percentage;
　　（ ） Repeatedly breath valve open several times, when the pneumatic valve in the closed position, applying full torque;
　　（ ） Repeat steps ( ） Or time.
　　. Tighten again and replace the
in the hours after operation, check the regulation of gland status, when it is necessary to tighten, when gland cannot be further adjustment, must change the packing.