Insugraf Formed Packing and Bonnet Seals

INSUGRAF formed packing rings and bonnet seals aremade by vertically placing INSUGRAF tape into a die and
compressed with a hydraulic press. The pressure exerted bythe press is determined by the based on the required densityof the ring. As the tapes are vertically placed into the die and the compression is also vertical there is the chance ofcrimping on the outer and inner diameter of the ring which arefrequently mistaken as cracks. These are actually crimps andnot cracks and are very important for the sealing rings as thishelps maintain resilience in case of pressure surges.Due to its multiple properties INSUGRAF packings are auniversal packing material in pumps and valves in diversemedia. When using INSUGRAF packings it is not necessaryto remove the entire packing as in the case of traditionalcompression packing as INSUGRAF does not undergo anychange in its sealing efficiency even after long-termcompression. So just adding another ring in the stuffing box issufficient and effective way to overcome delay in downtimecaused by constant change in compression packing.
Rings made from INSUGRAF tape are recommended for use in handling heat transfer fluids, oils, acids,
alkalis, hot water, feed water, hydrocarbon products as well as super-heated high-pressure steam. Not
only manufacturers of pumps and valves but also users have come to realize the importance of the preformed rings of INSUGRAF as it standardizes their requirement.
Although the preformed rings are manufactured from INSUGRAF flexible graphite tape it has an edge
over the at site wrap process which needs to be followed in case users buy the tape. The ways in which
this product is superior are:
1. Lack of universal winding tension which can lead to an uneven packing which causes leakage.
2. The tape is slippery in nature and thus cannot be well-handled by greasy hands.
3. It is time-consuming to tighten the gland followers each time.
On the other hand, the preformed rings are ready to use and formed in such a way that they fix exactly in
the place which is allotted to them. They are easier to place even more labor and time saving solution
than the INSUGRAF tape.
INSUGRAF packings are deigned to provide optimum seal efficiency. These are precision made
packings and need careful installation. Stuffing boxes should be in sound condition. The stuffing box
and shaft or spindle should be clean and smooth. The gap between the shaft and the housing at the
bottom of the stuffing box should not exceed 0.5mm. Before putting a valve or pump into operation the
spindle or shaft should be checked for freedom of rotation. In case it is too tight slacken off the gland
slightly. If there is a leakage reduce it by gradually tighteningthe gland. In case of very high temperature and
pressure conditions it might be necessary to add onemore stuffing box. For the best results special top and bottom headerrings are recommended when the packing is subject to extremes of high-pressure conditions orin case of excessive clearances. These headerrings act as wipers and prevent particle transfer.The rings are available in 2 forms, endless and splitin 2 halves with oblique cuts. To enhance thepressure handling capabilities of the rings it is also available with metallic wire reinforcement.

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