Upstream Pumping

Transforming the traditional concept of sealing

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Value and Advantages of USP Technology

John Crane’s unique, engineered, non-contacting USP seal face technology borrows from gas seal designs to deliver a breakthrough in liquid sealing technology. The typical mean time between repair (MTBR) for traditional seals is three years, while USP seals are more than five. Here are the benefits:

  • Extended MTBR
  • Nearly eliminates cooling water requirements
  • Energy savings
  • Zero-emissions
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Why USP?

USP seal face technology helps overcome the most rigorous sealing challenges. It improves seal and pump reliability, prevents unplanned downtime and reduces operating costs across a broad range of severe-service conditions, such as:

  • Low-lubricity conditions
  • Dry running conditions
  • High heat
  • Friction
  • Caustics/liquors
  • Viscous fluids
  • Polymerizing fluids/solidifying
  • Dirty fluids

It is also suitable for a variety of process industries with challenging process fluids, for example:

  • Chemical process liquids
  • Volatile organic compounds (VOCs)
  • Poor lubricity fluids
  • Sour services (H2S)
  • Foul water
  • Abrasives

How it Works

The basic concept of John Crane’s solution is that the conventional seal is replaced by a low-volume, high-pressure “pump”—the USP seal. This pump propels a minute quantity of barrier liquid along the path usually sealed by the mechanical seal faces and into the product side. Because the product side is at a higher pressure than the barrier liquid, this seal is said to pump “upstream.”

Mechanical seals require a narrow gap between faces to allow a lubricating film to work; the gap must also be optimized to eliminate leakage. Debris in process fluids can create deposits, damage faces and cause hang-ups. This is where USP comes in — it extends seal life and the MTBR of the pump.


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USP Support System for Optimal Performance and Reliability

Mechanical seals using Upstream Pumping seal face technology have support system requirements unique from traditional dual mechanical seals. A standardized support system is available to supply our standard Upstream Pumping seals. Using one of these systems eliminates the need to design a custom system, saving costs, making operation simple and minimizing space requirements. For more information on the GS USP–R and GS USP–D

Environmental Benefits

The Power of Water and Energy Savings

With USP, the quantity of water required for cooling is nearly eliminated. Energy usage is also significantly reduced compared to traditional sealing methods.

Reduce Your Carbon Footprint

John Crane supports your corporate CO2 emissions reduction strategies. 12.4 metric tons of COcan be saved annually by adding a John Crane USP seal to one pump.



Water Use

Power Use

Average Running

Traditional Seal

3 years

4,200 m3
(920,000 gallons)

19,500 kWh

= $4,200

USP Seal with GS USP
Support System

5+ years

4.9 m3
(1,070 gallons)

1,970 kWh

= $290

Net Results

2 years

4,195 m3
(918,930 gallons)
Water savings

17,530 kWh
Power savings

= $3,910
Net cost reduction

*Assumes a water cost of $0.35 per m3. Water cost varies greatly depending on geographical location and water source.
*Power cost is based on $0.142 per kWh, which is typical average cost for the US in Q3 2022.
Note: Additional savings for maintenance, such as cost to top-up reservoirs, cost for seal refurbishment or equipment
downtime are not included in this example and will also be realized.

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