Dragon Wholesaling 178 Series Installation, Operation And Maintenance Instructions - Page 11
Browse online or download pdf Installation, Operation And Maintenance Instructions for Water Pump Dragon Wholesaling 178 Series. Dragon Wholesaling 178 Series 16 pages.
Print Page2. Grease all five shaft packing rings (5). Insert three packing rings alternating the splits in the
rings from top to bottom starting with the split on the first ring on the bottom. If King type
packing is being used the rings should be installed with the lips toward the impeller.
3. Install the lantern ring with the split in the vertical position. The two halves of the
packing gland may be used to push the packing and the lantern ring together and to
the bottom of the box.
4. Insert the final two packing rings. The objective is to have the last split down so that leakage
will drip down and not have to go over the shaft and possibly in the bearings. If King packing
is being used, insert the final King ring with the lip towards the outside and split on top, and
follow with the single ring of square packing split down.
5. With the packing gland in position, swing the gland bolts into place. Initially tighten the gland
hard to compress the packing. Then back off the gland bolts and retighten only finger tight.
Caution: Tighten the gland against the packing finger tight only. If packing is
over- tightened it may be burned when the pump is started.
Excessive Packing Leakage and Rapid Packing Wear
Most early packing failures are caused by over-tightening or poor installation.
Packing Appearance
If the packing being removed is hard and brittle, it has been run dry some time in its life. This is
often done in the first hour of service. The packing has more ability to grow with heat during its
early life. Even if the packing is adjusted just right before starting the pump, in the first few min-
utes of operation the packing will grow with heat and become over-tight. It will then run drop-tight
and the packing will burn. ONCE THE PACKING IS BURNED IT WILL NEVER SEAL PROPERLY AGAIN.
Let new packing leak more in the first few hours and then adjust it to 10-12 drops per minute.
Installing Water Flush System to Be Acceptable By Oil Companies
Many oil operators will not allow water to be put on the packing because of excess water getting
into the mud, a result of poorly designed and maintained systems. Two major problems cause
this complaint:
1. Too much line pressure
2. Not turning water off when pump is not in use.
Controlling Water Pressure to the Packing
The water pressure is usually too high. The brake cooling pump is normally used which operates
at pressures from 50 to 75 psi. Only 5 to 10 psi water is needed to cool and lubricate the pack-
ing. A pressure regulator should be installed to reduce the pressure on the packing. One regula-
tor can supply all centrifugal pumps from a central system.
Controlling When To Use Water on Packing
LARGE VOLUMES of water get into the mud when the pump is NOT OPERATING. When the
pump is running, the shaft deflects and when stopped, the shaft straightens up and a gap occurs
down one side of the shaft between the packing and the shaft. This allows a stream of water to
enter the mud. You can manually turn off the water when the pump is shut down but a better way
is to install a solenoid valve in the water supply line that turns the water on and off as the motor
is turned on and off. ONLY a small amount of water (a few drops per minute) which gets into the
mud while the pump is running should not be objectionable to the oil companies.
Bearing Failures
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