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Sullair 250033-821 is the complete minimum pressure check valve fitted after the separator tank. It is used on Sullair rotary screw air compressors. This aftermarket version is made to the same mounting and connections as the original, so it fits where the old one came off.
Sold as one unit. Check the number on your old part, or in the parts manual for your machine, before ordering.
| Part Type | Minimum Pressure Check Valve |
| Replaces | Sullair 250033-821 |
| Type | Minimum pressure and check valve, cast iron body with spring cartridge |
| Supplied | Complete valve assembly (not the repair kit) |
| Condition | New, aftermarket |
| Stat. HS-Code | 848180 |
| Sullair Part No.(SPM Part No.) |
|---|
| 250033-821(SPM-ACP-2738) |
Slow pressure build up on start
The minimum pressure valve holds pressure in the separator tank so oil circulates before air goes to the plant. A valve stuck open lets the tank pressure drop and the compressor can carry oil over or run hot.
Oil carry over
Low separator pressure from a leaking minimum pressure valve is a common cause of oil in the air lines. Check the valve when the separator element is changed.
Air flowing back on stop
The check function stops plant air flowing back into the compressor when it unloads or stops. A worn seat lets air leak back through the separator.
Fitting tips
Isolate and vent the compressor completely before opening the valve. Fit new seals and check for leaks at working pressure before putting the machine back to work.
We check what other aftermarket sellers charge for this same part. Their prices on the date we checked:
| Seller | Price | Checked |
|---|---|---|
| eBay (5 aftermarket sellers) | USD 347.00 to 500.00 | 6 Oct 2026 |
| Spare Part Mart | USD 325.22 | Today |
Our price of USD 325.22 is 6% to 35% less than these sellers.
Found this part cheaper somewhere else? Send us the listing and we will beat it by 5% under our Price Beat Guarantee. Every order is also covered by our 30 day money back guarantee.
No. It is an aftermarket part made to fit in place of Sullair 250033-821. It is not made by or affiliated with Sullair; the Sullair part number is used only to show what it replaces.
It fits machines that take Sullair 250033-821. Machines change parts between serial number ranges, so check the number on your old part or in your parts manual.
It is made to the same mounting and connections as the original part. Fit new gaskets and seals where they are used, and check for leaks and correct operation before putting the machine back to work.
Yes, we ship worldwide. Shipping is calculated at checkout, and every order is covered by our 30 day money back guarantee and price beat guarantee.
Orders typically require 1 to 5 business days for processing. During this time, we confirm product availability and prepare the shipment for consolidation.
We offer two shipping tiers. The exact cost and transit time for every option are quoted live at checkout, and you can also check them from the cart page before you buy.
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For urgent needs. Transit is typically 3 to 8 business days after dispatch, depending on destination.
Economy (air cargo and special lines)
Our standard, cost-effective option. Transit is typically 5 to 15 business days after dispatch.
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For detailed delivery information and FAQs, please visit our Delivery Information page or contact us.
Prices depend on your postcode.
In USD for the quantity selected. The exact cost is confirmed at checkout.


