Mechanical Seal Tools, Selection, Sizing and Cost
Practical tools for specifying a seal, sizing an O-ring and proving what a failure really costs. Free, no account needed.
The Tools
Mechanical Seal Selector
Five questions on fluid, temperature, pressure, solids and criticality. You get an elastomer, a face pair, an arrangement and the watch-outs for that duty.
Use it when you know the application but not the specification.
Seal Total Cost of Ownership Calculator
Model what a seal failure actually costs: replacement parts, labour hours, lost production and callout time, against the price of getting the material right first time.
Use it to justify a better specification to whoever signs the order.
Sealing FAQ
Direct answers on seal types, elastomers, refurbishment, lead times and how we work.
Use it for quick answers before you pick up the phone.
Five Step Selection Method
The written method behind the selector, with seal types, face pairings, elastomer limits and application notes.
Use it when you want the reasoning, not just the recommendation.
Seal and O-Ring Sizing Checklist
Gather these six things before you specify or order. With them, almost any seal or O-ring can be identified, including obsolete and non standard sizes.
Shaft or sleeve diameter
Measured where the seal sits, not at the coupling. This is the single most important figure.
Seal chamber bore and depth
Decides whether a cartridge seal will physically fit or whether a component seal is needed.
Axial space available
Measured from the chamber face to the impeller or the nearest obstruction.
O-ring groove dimensions
Groove inner diameter, width and depth. Measure the groove, never the old ring.
Standard and code
AS568 for imperial O-rings, BS ISO 3601 for metric. Quoting the code removes all ambiguity.
Duty conditions
Fluid and concentration, temperature, pressure, shaft speed and any approvals you must meet.
No catalogue size fits? See large diameter O-rings made to your groove dimensions.
How to Check Chemical Compatibility
1. Name the fluid properly
Trade name plus concentration. A 5% solution and a 98% solution are different chemical problems.
2. Use the real service temperature
Compatibility ratings shift with heat. Rate the elastomer at the hottest condition, including CIP or steam cleaning.
3. Check the whole stream
Cleaning chemicals, flush fluids and trace solvents attack seals just as effectively as the main product.
4. Consider pressure and gas
Gas service with pressure cycling needs a rapid gas decompression grade, whatever the chemistry says.
5. Sanity check the cost
If a cheaper elastomer covers the duty, use it. FFKM is often more material than the job needs.
Detail on the hardest chemistry sits in the FFKM chemical compatibility guide and the FFKM vs FKM comparison.
Common Questions
Is the mechanical seal selector free to use?
Yes. It runs in your browser, takes about a minute, and you only share contact details if you choose to send the result to us for confirmation.
How accurate is an online seal selector?
It gives you a sound starting specification from the same logic an engineer would apply: chemistry sets the elastomer, solids and dry running set the face pair, and criticality sets the arrangement. It is not a substitute for confirming an unusual or safety critical duty with a specialist.
What does the TCO calculator include?
Parts, labour, downtime and repeat failure frequency, so you can compare the cheapest seal against the one that lasts. The output is only as good as the hourly downtime figure you put in, so use a realistic one.
Which tool should I use to size an O-ring?
Sizing comes from the groove, so start with the sizing checklist on this page: groove inner diameter, groove width and groove depth. Then use the selector for the material. Send both to us and we will confirm the size and compound.
Can these tools help with chemical compatibility?
The selector asks for the fluid and temperature and recommends an elastomer on that basis. For aggressive, mixed or high temperature chemistry, read the FFKM chemical compatibility guide alongside it.
Do I need part numbers to use the tools?
No. The tools are designed for the situation where you have a pump and a problem but no paperwork. Dimensions and duty conditions are enough.
Prefer to read first? All the written material is in the guides library.
Free PDF: 40 Reasons Mechanical Seals Fail
Field diagnostic reference covering installation, material, operating and maintenance causes.