Recent advances in Gland Packing (Part -2)

In-Situ Mold

In Part 1 of the article we had discussed the concept of Reinforced Yarn Packing and In-Situ Mold. In-Situ Mold has been designed for scored and pitted shafts in pumps and valve stems. Regardless of size and shape of the stuffing box, In-Situ Mold forms itself to the configuration of the box and shaft, and compensates for wear by remolding itself.

In –Situ Mold is recommended as a supplement to polished rod stuffing boxes, centrifugal and for valves. It is highly recommended locations where equipment shut down causes critical conditions. In-Situ Mold service temperature 600°C, and pressures to 20,000psi and surface speeds upto 1,000 fpm. In-Situ Mold is unaffected by acids, oils, caustic of common solvents.

When 2% of conventional packings wears out 90% of the packing must be discarded and wasted, when this wear occurs, In-Situ Mold may be added to the stuffing box removing only enough old packing to accommodate it. Used as a supplement. In-Situ Mold stick packing can salvage the worn conventional packing, reducing packing cost by as much as 90%. In-Situ Mold also reduces labour costs, inventory and down time resulting in a additional savings.

Installation is simple. Apply In-Situ Mold in whole stick from or break in small. In-Situ Mold may be applied to stuffing boxes with high fluid pressure or excessive tolerances. In-Situ Mold is pliable and can be easily inserted into any size pump or valve stuffing box. The moldability is demonstrated here being applied to the shaft. In-Situ Mold is clean, Odorless and flexible for fast, time saving application.

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Hollow Core Packings

The Hollow Core Packing has been developed low speed shaft having whip. Due to constant deforming and reforming the Hollow Core Packing maintain contact with shaft /sleeve thus providing proper sealing. Whereas in the case of conventional packing due to constant impact of shaft “COMPRESSION SET” develops as result the packing becomes glazed and hard. The gases and or vapour that where intended to be trapped inside the vessel to complete the reaction escape and the quality and yield of the process is effected. The Hollow Core Packing provides sealing from the inner most ring, there is very less load on the shaft /sleeve, hence wear and tear is almost negligible. Months of in-plant testing have proved that hollow core packings outlast conventional packings in applications associated with excessive shaft run-out. The patented Zero Compression Synthetic Yarn Packing is the latest addition to the family of advanced fluid sealing products. It is designed after years in research and interaction with users in industry. The packing has been designed for the most demanding and critical sealing applications throughout the chemicals and processing industries. The packing is composed of PTFE/Graphite yarn reinforced with patented synthetic fibre. Reinforced Yarn Gland Packings exhibits excellent recuperation. To further enhance the recuperation properties Stoplik has introduced ZERO COMPRESSION GLAND PACKING.

In case of a mechanical seal, the seal faces crack due to excessive thermal stresses arising out of lack.

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Behaviour pattern of Zero Compression Packing.

Behaviour Pattern of Inter Lube Reinforced Packing.

faces, improper cooling or excessive seal face deflection. The zero compression packing exhibits excellent self lubricating characteristics with excellent heat transfer property. These packing have been successfully installed in number of cases where mechanical seals have failed frequently.



For the maintenance man it indeed is very difficult or rather impossible to visualize a gland packing without leakage. However reinforced yarn packing with zero compression needs to be installed to believe this impossible phenomena of stuffing box without leakage. The other benefits accrued include low maintenance costs, no pollution problems, reduced packing material cost, energy conservation higher production and improvement in overall all plant productivity.


Case Studies

  • A reputed chemical manufacturer reported of leakages of acidic fumes from the stuffing box of the sulphonator. The acidic fumes from the stuffing box of the sulphonator. The acidic fumes were highly hazardous & harmful to the operating personnel and environment. The sulphonator had 120mm dia shaft rotating at 90 RPM. Conventional imported PTFE/Graphite Packings used had a life ¾ weeks, the packing ring hardened in the service and there was continuous leakage of acidic fumes, which ultimately damaged the sleeve and scored the shaft. The sulphonator was repacked with Stoplik Hollow Core Packing and In-Situ Mold sticks. This combination provided optimum sealing & the packing was in good condition when it was removed from the stuffing box during routine plant shut down. Pollution was eliminated , Expensive chemicals conserved & plant downtime reduced.
  • A bulk drug manufacturer had a problem of leaky stuffing box of agitator reactor vessel handling organic solvents and 130°c under vaccum of 660mm of Hg. Conventional PTFE impregnated asbestos packing was ineffective. Leakages of solvent (100 Liters /batch) with scoring of shaft and run out of 1mm were reported. The stuffing box was repacked with Stoplik Hollow Core Packing with In-Situ Mold. This packing provided optimum sealing with a service provided more than 400 batches. Substantial savings due to prevention in solvent losses and downtimes were reported.
  • A pesticide manufacturing plant had a agitator reactor vessel operating at 210°C under vacuum of 700 mm Hg. The reactor had a shaft dia of 110 mm and RPM of 72.Imported PTFE & PTFE/Graphite Packings were ineffective. Leakages were reported resulting in vaccum loss, thereby increasing the batch time by almost six hours. Further the shaft had a run out of 2.5 to 3mm. The stuffing box was repacked with Stoplik Hollow Core Packing with In-Situ mold. This combination reported of excellent sealing with no vaccum loss. Batch time was reduced to 18 hours instead of 24 hours. The packing lasted for more than 65 batches. The plant reported of higher production & low downtimes. For any further queries please feel free to contact at :

Kirit Kumar Nanani-Director,
Plot no A/465, Road no.28, Wagle Industrial Estate, Thane -400604.,(Mah.), India.
Ph.: 022-61597100 / 101 / 102
Fax : 022-25822564
Website :