Where do Kalsi Seals® fit in the fluid sealing industry?
Our rotary sealing niche in the fluid sealing industry
The fluid sealing industry encompasses a wide variety of product categories such as valve packing, gaskets, rotary seals, hydraulic piston and rod seals, O-rings, diaphragms, expansion joints, wiper seals, etc. Each of these product categories contains a diverse array of specialized products. For example, the rotary seal category includes products for specific conditions and applications, such as mechanical face seals, garter spring energized radial lip seals, hydraulic cap seals, etc.
The Kalsi Seals niche in the fluid sealing industry is polymeric rotary seals that have significant pressure capacity and retain a lubricant. One feature of Kalsi Seals that promotes pressure resistance is a wide dynamic sealing lip that provides both strength and sacrificial material to accommodate wear. Another feature is optional composite construction that positions a stiffer more extrusion resistant material at the extrusion gap clearance between the shaft and the equipment housing.
The lubricant side of the dynamic lip of a Kalsi-brand fluid seal incorporates a pattern of hydrodynamic waves. These waves engage the shaft and use shaft rotation to produce a pumping action that forces a thin film of lubricant into the dynamic seal-to-shaft interface. This lubricant film lubricates the seal, which dramatically reduces friction-generated heat and wear, and reduces the temperature-related loss of seal material properties.
The Kalsi Seal product line includes seal geometries for operating conditions that range from clean to contaminated fluids and from high lubricant pressure to high fluid pressure. An overview of our fluid sealing products is included below.
Fluid seals for pressure acting toward the lubricant side
KLS® lip seals are spring-loaded lip-type fluid seals for unidirectional rotary operation. Patented hydrodynamic waves on the pressure-resistant plastic liner contact the shaft when differential pressure acts across the seal from the spring side. The lubricant film these waves generate during shaft rotation allows operation at significantly higher pressures (1,000 psi at 542 sfpm and 1,500 psi at 136 sfpm), compared to conventional spring-loaded PTFE lip seals.
When retaining pressurized abrasive fluids, we recommend using KLS-type fluid seals in pairs, with a barrier lubricant between the seals that is pressure balanced to the abrasive fluid. This protects the inboard seal from abrasives, protects the outboard seal from high pressure, and provides redundancy. Pressurization of the barrier lubricant can be accomplished with one or more small pressure compensation pistons. Contact us for additional implementation guidance.
Kalsi washpipe packing is interchangeable with the conventional packing used for high-pressure drilling fluid sealing in oilfield washpipe assemblies and has the same fabric reinforced construction. What makes it better is the grease inlets that engage the shaft when pressure acts across the packing ring. These patented inlets promote lubrication of the washpipe-to-packing interface, which produces noticeably cooler operation in difficult high pressure, high speed operation. Click here for available sizes and additional information.
Fluid seals for pressure acting from the lubricant side
All of our fluid seals for pressure acting from the lubricant side can be paired with other seals to retain pressurized non-lubricating fluids, as shown schematically in Chapter D1 of our sealing handbook. More detailed implementation guidelines are provided in Sections D and E of the handbook.
Plastic Lined Kalsi Seals have a hydrodynamically lubricated pressure resistant plastic liner that is loaded against the shaft by the radial compression of an HNBR seal body. They have the highest pressure capacity of all the fluid seals offered by Kalsi Engineering, and have survived hundreds of hours of operation at 141.4 to 206.2 sfpm (0.72 to 1.05 m/s) while retaining a ISO 68 viscosity grade (VG) lubricant at 9,500 to 10,000 psi (65.50 to 68.95 MPa). They have also survived a thousand hours of operation at 240 sfpm (1.22 m/s) while retaining an ISO 150 VG lubricant at 7,500 to 7,800 psi (51.71 to 53.78 MPa). They are suitable for clockwise and counter-clockwise rotation. Contact our staff for additional information.
Elastomeric Kalsi Seals are manufactured in single material and dual durometer versions and are available in a variety of lip widths, hydrodynamic wave patterns, and seal materials for different service conditions. Wider lips have more strength for improved resistance to lubricant pressure and provide more sacrificial material to address wear mechanisms such as abrasive wear and pressure-related extrusion damage. Generally, wider lips have higher torque and require more aggressive hydrodynamic waves to assure adequate lubrication. For an introduction to the various types of elastomeric Kalsi Seals, see our online seal catalog or contact us for assistance.
Our single material seals are typically used for the lower end of the high-pressure service range, and for partitioning seal lubricants from process fluids, such as oilfield drilling fluid.
Dual Durometer Kalsi Seals use a layer of higher modulus elastomer to define the inner portion of the dynamic lip. To avoid excessive contact pressure with the shaft, the higher modulus layer is loaded against the shaft by compression of a lower modulus outer seal body. This fluid seal construction method provides added high-pressure extrusion resistance compared to single material seals by positioning the higher modulus material at the clearance gap between the shaft and the housing. In our highest pressure test of Dual Durometer Kalsi Seals, a pair of 2.750” (69.85mm) seals with our “Extra Wide” dynamic lip width were supported by floating backup rings and tested for 40-days at 5,000 psi (34.47 MPa) and 252 sfpm (1.28 m/s) with 0.010” (0.25mm) dynamic runout FIM.
Fluid seals for oil pressure acting in either direction
BDRP seals™ are a design variation of the Plastic Lined Kalsi Seal that retains high oil pressure acting in either axial direction. They have the same extreme pressure capacity as extra wide seals when the pressure acts from the wave side of the seal. With pressure In the opposite direction, these unique fluid seals have been tested at 1,000 psi (6.89 MPa) with a shaft speed of 467 sfpm (2.37 m/s) and have been tested at 1,500 psi (10.34 MPa) with a shaft speed of 275 sfpm (1.39 m/s).
These are the most capable fluid seals we have for applications that do not have a pressurized lubricant supply, such as lower cost oilfield rotary control devices (RCDs). In such applications, where a pressurized abrasive fluid is being retained, we recommend using an outboard barrier seal, with the pressure of the region between the BDRP and the barrier seal balanced to the pressure of the abrasive fluid. Contact our engineering staff for additional information.
Contact our fluid sealing engineers for assistance
Kalsi Engineering, Inc. was founded in 1978 and has over 50 years of fluid sealing experience. The graduate student research of the company founder led to a rotary shaft seal product line that features hydrodynamic lubrication of the seal-to-shaft interface. Our state-of-the-art products are the fruit of our longstanding investment in fluid sealing research. Contact us for engineering and sales assistance.