The company R&PC «ANOD» received for repair a set of dry gas dynamic seals manufactured by the company «TREM-Kazan» operated by the gas transportation division of LLC «Gazprom Transgaz Ukhta».
Photo1. The appearance of a dry gas dynamic seal after the repair
Technical characteristics:
- Type of seals: tandem, reverse rotation.
- Shaft diameter, mm: 188.
- Pressure, dynamos. ,MPa: 5.51 — 7.21.
- Pressure, stat., MPa: 6.03 — 7.9
- Nominal number of compressor rotor revolutions per minute: 5250.
- The material of the friction pair rings: silicon carbide.
- Pumped medium: natural gas.
The seals were dirty, the rings of the friction pairs had wear and damage in the form of chips from the anti-turn pins. Polymer and rubber O-rings have lost elasticity. During the repair, the seals were cleaned of dirt. Springs, fasteners, polymer and rubber sealing rings were replaced. The damaged metal parts were manufactured again, some of them were coated with a special coating that allows to increase the service life of the seal. An example of such a detail is shown in photo 2.
Photo 2. Dynamic sleeve of dry gas-dynamic seal with wear on the working surface.
The damaged rings of the friction pairs were replaced with new ones, followed by the application of a diamond-like coating. After successful factory tests in December 2021, the seals were transferred to the customer for further operation.