Operating Experience with Diamond Coated Seals

Single mechanical seals with hard/hard face combination and with a non-pressurized quench are a cost-effective and low-maintenance seal system for multiphase pumps, which have to deal with a high content of gas and solids.
In multiphase applications silicon carbide seal faces are limited to low pressure differences, due to insufficient lubrication of the seal faces at a high gas volume fraction (GVF). DiamondFace® seals have an excellent performance under poor lubricating condition and thus can deal with an increased pressure differences even at high GVF’s.
A twin-screw multiphase pump was equipped with four single DiamondFace® seals in order to check the seal performance at high pressures and high gas contents. After 150 h of operation at 24 bar sealing pressure and 95% GVF and after 50 Start/Stop the seals have been inspected. All seals passed the test with an acceptable operating performance and without any signs of degradation.