Grafseal Tape
An advanced and adaptable valve stem/pump shaft packing material used for gland or stuffing box packing at site. The self winding method and forming the required size of the gland packing at site is very practical and simple, especially as any dimension can be prepared quickly.

Method: A Pre-determined length of tape depending upon the radial width (the space between stem or shaft and the cylinder bore) is wrapped around the stem or shaft until the stuffing box is filled. The wound tape is then pushed down into the stuffing box and compressed to half its width by close fitting split pushers and the gland follower. With the help of a scale before and after compression of tape, the packing mechanic will be able to judge the extent of compression achieved. The stem or shaft under gland load should be turned every time before the next ring is formed. This process is repeated till the depth of the stuffing box is full.

SPITMAAN GRAFSEAL TAPE has infinite shelf life and can be kept in readiness in every store as a part of the maintenance kit. By using the tape the inventory of preformed rings of different types and cross sections can be reduced to a minimum, offering advantages with regard to maintenance and repair work.

GRAFSEAL Tape brings down the inventory to only a few rolls of tape of different thicknesses and widths. These Tapes are also available with adhesive backing to form gaskets on a " Do It At Site " basis.
 

Grafseal Formed Packings
Advantages in use of Formed Packings
Due to its multifarious properties GRAFSEAL enables variety of packing materials to be reduced resulting in saving in storage and inventory costs.

GRAFSEAL Packings are self lubricating, with the result wear on moving parts will be minimum.
As a result of the high thermal dissipation property, it is not necessary to have gland cooling arrangement. This results in saving of operational cost.

When GRAFSEAL Packings are used, it is not necessary to remove the complete packing from stuffing box, even when it is compressed after prolonged use. Due to the exceptional characteristics of the material GRAFSEAL does not harden or undergo any change, affecting its sealing efficiency. Therefore, only adding one additional ring to the stuffing box solves the problem. The use of GRAFSEAL packing minimises downtime as compared to conventional packing.

GRAFSEAL Packing Rings are recommended for use in valves and pumps handling heat transfer fluids, oils, acids, alkalies, solvents, hot water, boiler feed water, hydrocarbon products as well as super heated high pressure steam. GRAFSEAL Packing are excellent for Nuclear Services. The "Chloride content" of this packing is kept much below the permissible values. In radiation atmosphere, especially the packing mechanic will be able to spend limited time for packing valves and pumps. Precision moulded packing will therefore be safer and advantageous.

It is not only the pump and valves manufacturers who draw benefit of this cost-saving GRAFSEAL ready made Rings, but also other actual users who realising the importance of preformed Rings have standardized their requirements, on this packing Pre-formed GRAFSEAL rings have distinct advantages as compared to preparing the rings from Tape on a " Do It At Site " basis.

Some of the shortcomings in using the Tape are :

• lack of uniform winding tension, due to physical obstruction in one particular orientation,
• or the slippery nature of the product when handled by greasy hands,
• the time consuming necessity to compress and tighten the gland followers each time.

On the other hand, ready made rings are formed in such a way that they fit exactly into the space provided for them. They possess sufficient compressibility and resiliency. These rings have uniform density, smooth finish, close tolerance and also save labour and wastage. Due to their special construction, formed packing rings offer uniform axial and radial expansion.

GRAFSEAL Packings are designed to provide optimum seal efficiency. These packings are precision made; and need careful installation. Stuffing boxes should be in a sound condition. Stuffing box and shaft or spindle surface should be absolutely clean and smooth. The gap between the shaft and the housing at the bottom of the stuffing box should not exceed 0.5 mm. 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 sightly. If there is a leakage, reduce it by gradually tightening the gland. In case of very high pressure applications, it may be necessary to add one more ring to the stuffing box.

For best results, special top and bottom header rings are recommended with the packing set especially when the packings are subject to extremes of high pressure conditions or in case of excessive clearances. These header rings prevent extrusion and act as wipers to prevent particle transfer.

While ordering GRAFSEAL Packing Rings, service conditions viz., temperature, pressure, and the medium to be sealed should be indicated.
GRAFSEAL Packing Rings are supplied in three forms, endless, split and in two halves.

Rings

• Endless
• Split
• In 2 halves: Oblique or Straight cut

Sizes in all types can be supplied as per customer's specification.

Grafseal Gaskets
GRAFSEAL Gaskets are premium products for flanges capable of withstanding extremes of temperature and pressure. These gaskets are also suitable for flanges of enamel or glass. GRAFSEAL Gasket will not damage these sensitive flanges, as it contains no binder or filler and its characteristics remain constant.

Properties:

• The resiliency and compressibility of the Gasket is excellent; it can easily adapt to any flange irregularities even at low surface pressures. If the GRAFSEAL Gasket is compressed further during assembly, resiliency increases with the result that the gasket can behave dynamically from cryogenic to molten metal temperatures (-200°C to +3000°C).
• Even with frequent temperature and load changes or vibrations, GRAFSEAL Gaskets remain dimensionally stable and provide a complete leak proof joint without embitterment or hot/cold flow characteristics. It is possible to seal even flanges which are corroded or pitted with GRAFSEAL Gasket without spending time working over the flange. These gaskets have extraordinarily good thermal stability and co-efficient of expansion similar to Steel. Non- metallic gaskets are recommended for pressures upto 200 kg/cm2 and metallic gasket upto 800 kg/cm2.
• The high performance characteristics of GRAFSEAL Gaskets ensure operational efficiency, longer life, reduced maintenance and hence they are economical to use when compared to conventional gasket materials.
• These gaskets have no ageing characteristics and remain leak proof under moderate bolt loads and do not require precision bolt tightening.

Grafseal Universal Adhesive Gasket Tape
GRAFSEAL gasket tape, an all graphite product, is self adhesive. It has extremely good elasticity, compressibility and can form a perfect seal even at elevated temperatures and pressures generally encountered in the industry. It is an acknowledged fact that GRAFSEAL adhesive tape has universal applications since maintenance personnel can fabricate gasket on flanges in the site itself of the required size and shape. The inventory is brought down to a few rolls of GRAFSEAL adhesive tape of different widths which will take care of the most of the gasket requirements of the entire plant.
At high temperatures, the adhesive backing carbonizes and becomes an integral part of the gasket itself.

Before using these tapes the following points may be observed:

• The flange surface should be thoroughly cleaned to remove rust, foreign particles, grease or oil.
• Thereafter, peel of the paper backing six to eight inches and start laying tape on the flange and press against it. When the tape reaches the starting point, lap the tape not more than 2 mm and cut with a sharp knife.
• For additional thickness when the starting point is reached, do not cut the tape but roll out the flutes in the already formed gasket with a smooth roller and repeat step 2 above. It is important that the top layer is positioned EXACTLY above the first layer already formed.

Service:
The service conditions are the same as detailed for other GRAFSEAL products.