A new video shows how easy it is to assemble a high pressure washpipe assembly that incorporates our patent-pending floating metal backup rings and hydrodynamic rotary seals. The backup rings are radially pressure balanced and axially force balanced. The radial pressure balance makes them relatively immune to pressure induced deformation, which allows for a more consistent extrusion gap clearance for the mating rotary seal. The axial force balance allows the backup ring to float laterally to align on the washpipe. This combination of features allows the use of the smallest practicable extrusion gap clearance, which reduces pressure-induced damage to the rotary seal. These features and benefits are explained, as the relevant components are assembled.
The key to easy assembly is our stacked housing arrangement, which is readily adaptable to other types of equipment, such as side entry cement swivels and rotary control devices (RCDs). One thing that facilitates assembly is the elimination of difficult-to-assemble, failure-prone radially sealing O-rings. Another factor is the elimination of the conventional pressure housing, which means that no components are required to have a tight fit with the bore of a pressure housing.
For more information about the high pressure washpipe assembly, see Chapter E4 of our rotary seal handbook, or contact our staff. See Chapters E2 and E5 of the handbook for tips on how to use our stacked housing, floating backup ring arrangement in extreme pressure side entry swivels and oilfield cement heads.