Installation guide for the hottest packing

2022-08-05
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Guide for installation of sealing packing (packing)

I. preparation before installation of sealing packing

removing old packing and checking the stuffing box are the key points for early installation preparation

before packing, take out all the old packing with special column 4 tools for key cultivation fields of leading enterprises, clean the stuffing box, and observe whether there are damage, eccentricity and other defects at all parts of the stuffing box. The damaged valve rod, shaft sleeve and stuffing box can affect the packing performance

check whether other parts can be applied. Replace all damaged parts

II. Selection of proper packing for sealing packing

two things must be considered when selecting packing

working condition requirements shall be consistent with packing performance. The packing that can best meet the requirements can be selected according to the relevant technical data. If in doubt, consult your sales representative

the packing size must be correctly selected according to the sealing requirements. In order to determine the cross section, please use the following formula to calculate:

cross section = (stuffing box diameter - valve stem diameter)/2

damaged devices may need packing with a slightly larger cross section to make up for the damage. If you have any questions, please contact us by telephone or letter

III. cutting and installation of sealing packing

1. Select the appropriate packing, and use the cutting machine to accurately cut the packing ring of the required length. If there is no packing cutting machine, cut according to the packing length l= (shaft diameter d+ packing width s) x1.07x. Generally, 90 ° straight cutting is used on the rotating shaft, and 45 ° cutting is used on the valve. Never attempt to determine the length by packing around the stuffing box. Or wrap the packing around a pipe with the same O.D. as the valve stem and press it tightly, but do not stretch the packing. Then cut it into sample ring, and check whether it can fill the space correctly, and ensure that there is no gap at the interface. The sample ring can then be used as a standard to cut other packing rings. If these finished products are finished on the plane, if the packing is soft or easy to deform, a small belt can be made according to the sample ring, and then the remaining packing ring can be made according to the rope

2, no wonder some people say that when the packing is used for the valve, the cross section of the packing is the same as the space of the valve. It is best to use the preloading ring: when used for the pump, the cross section of the packing and the space of the valve (about 0.3mm-0.6mm) provide a leakage gap between the shaft and the packing, which is conducive to lubrication and heat dissipation

3, install one packing ring at a time and make sure that each packing is free of dust or other debris. If required, the packing ring should be lubricated with the same clean lubricant used on the valve stem. Install each packing ring at 90 ° in a staggered manner. The ring is slowly pulled apart in the axial direction, and the radial distance is enough to enable the ring to be installed on the shaft. Use professional filling tools to fasten each packing ring. When enough packing rings are installed, the valve gland shall reach 25% of the packing thickness of the packing box, and the pump shall have 50% of the packing thickness. It is closed with a follower, which can increase the tightness. Remember that the follower is only a supplement; It can ensure the proper position of all packing rings and avoid the movement of packing

4, in the reciprocating pump, guide rings shall be placed at both ends and in the middle of the stuffing box to maintain its concentric movement and the gravity of the plunger

5, tighten the bolts after installing the packing ring. In order to obtain one to one pressure on each nut, it is a breakthrough in the industry to build in the color of vehicle interior decoration. It is recommended to use a wrench or relevant measuring device to tighten the nut. Note: if the device is in a leak free state at this time, it may cause packing combustion. It is recommended to slowly tighten the bolts until the leakage reaches the allowable range

IV. before the start-up of rotary and reciprocating pumps

and operation, the test run shall be conducted under no-load condition to observe whether there are any abnormalities, and then the formal start-up and careful observation shall be conducted to see whether there is any phenomenon that the pressure is not solid or too tight, resulting in serious leakage or burning of the packing. The key to starting the pump is to make sure that it leaks at the beginning. If the packing is tightened to be leak free at the beginning, the packing will be burned and cause leakage

after installing the packing ring, tighten the bolts and confirm that the material cover and the stuffing box face are correctly connected. Once the bolts are tightened, ensure that each bolt is evenly stressed

if an external lubrication system is applied, make sure it works correctly before starting

high leakage rate is allowed at startup. During this process, the packing is positioned and begins to function

after about minutes of operation, tighten the bolts again until the leakage reaches the allowable range. Recommended leakage points/min. Tetrafluoroethylene packing shall allow a greater flow rate to derive heat energy to reduce thermal expansion

v. valve startup

in most cases, the valve is designed to have zero leakage. In order to meet this requirement, the packing must be fully tightened with reference to the valve pressure

VI. installation guide for valve packing

1. strictly follow the installation guide for pump packing

2. rotate the valve bolt back and forth to ensure that it rotates freely

3. check the valve before operation. If leakage is found, refer to the relevant safety maintenance procedures and the manufacturer's recommendations for the problem of material test travel: appropriate adjustment. (end)

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