What's the Best Pump And Mechanical Seal Technology?
The 'Best Technology' phrase comes up in recent government regulations and per day plant conversations. So exactly what is the best Mechanical Seal and Pump Technology available now?
Here is my opinion:
Identifiable face materials compatible with the fluid to be sealed and any cleaners or solvents exposed to the designs.
Materials equipped to handle the full temperature array of the product you are sealing. Viton compatible with water. Hard faces that are not sensitive to temperate change or caustic cleaners. Unfilled carbon graphite seal face. No elastomers with shelf life. No stainless steel springs or bellows.
The seal should shut with both spring and system hydraulic pressure. Hydraulically balanced designs for low heat production. Two way balance in dual seal designs. Internal pumping ring for cartridge dual seals. Tandem configuration in dual seal models. No rotating 'back to back' designs. Stationary configuration for non-cartridge applications. Self aligning design for stationary cartridge different versions. Springs located out of the liquid.
The elastomer should for you to a clean surface simply because faces use. No spring loaded elastomers. Non fretting designs. Outside of shaft tolerance and result.Static elastomer located away for the seal features.Cartridge sleeve sealed at wet end. Vibration damping with the seal body. Seal should be located close to bearing technical support. No elastomer in the seal deal. Faces in compression.
Wide operating range. Low hysteresis. Equal & opposite clamping of stationary face. Sealing fluid located at the outside diameter of the seal people. Leak detection capability. Separate from shaft finish and tolerance. Compensate for thermal expansion and adjustments. Meet fugitive emission standards.
Simple installation. Eliminate all elastomers if possible. Short length leaving room for a shaft support bushing. Finite element analysis of all components. An approach of supporting the shaft in the event of a bearing failure. Trapped gaskets.
Packaging to live an one meter put. Back up sealing. Erected in seal face vent for vertical strategies. No glued elastomers in split seal configurations.
BEST PUMP TECHNOLOGY
Low shaft diameter to length rate. L3/D4 less than 60 (2 in metric). Large operating window
C or D frame adapter to simplify driver to pump alignment. Centerline design for thermal expansion. Oversize stuffing box. Suction recirculation with only a few exceptions. Adequate bearing retention (no snap rings). Positive bearing plugging. Oil level indication. Oil cooling ease of use.
Double volute to prevent shaft deflection.Suction specific speed number below 8500. Dynamically balanced rotating assembly. Impeller specific speed number selected for use. Duplex metal impeller. Impeller investment cast. Adjust impeller throughout the wet end to prevent mechanical seal face load change.