John Crane Inc.

Douglas J Volden

James P Netzel

James R Wasser

Richard Hosanna

Michael G Kalodimos

Syed Niamathullah

Thomas Steigerwald

A mating ring for use in a dry gas seal and a dry gas seal. The mating ring includes a face that defines an inner diameter and an outer diameter. The face includes: a channel formed therein disposed between the inner diameter and the outer diameter; one or more inlet channels formed in the face that extend from the inner diameter to the channel; and one or more spiral grooves in fluid communication with the channel that extend from the channel toward the inner diameter. Alternatively, the one or more inlet channels can extend from the outer diameter to the channel and one or more spiral grooves can extend from the channel toward the outer diameter.

Ring with recirculating grooves for dry gas seal

A mechanical end face seal with a pair of annular relatively rotating seal face defining seal rings. An annular compression contact ring disposed in surrounding relation to one of the seal rings includes a plurality of pads at asymmetrical locations in interference contact with the outer cylindrical surface of the ring.

Mechanical seal with banded ring

This invention relates to barrier seal systems for sealing the annular space between a housing and a rotating shaft which extends through a bore in the housing. The seal system has inboard and outboard mechanical end face seals. The inboard seal faces have spiral grooves for pumping a buffer fluid from a buffer chamber between the two seals toward the high pressure side of the inboard seal. The primary ring of the inboard seal may be double balanced. For high pressure applications, the buffer fluid may be pressurized and a pumping ring may be included in the outboard seal to circulate buffer fluid. High pressure applications also require two hard seal rings and optimum dam and face widths. Buffer fluid can be supplied to the seal system by a reservoir connected by a gravity feed line. A buffer fluid containment device may be attached to the high pressure side of the seal to prevent process fluid from contaminating the seal faces or secondary seals.

Barrier seal systems

A double, back to back oriented mechanical end face seal arrangement for use in sealing pumps or other devices used in fluid transfer of toxic or corrosive fluid has an intermediate buffer fluid chamber into which a relatively inert gas, such as nitrogen, is provided for use as a buffer fluid, and is maintained at a pressure which exceeds the process fluid pressure by at least 10 p.s.i. Each seal has a primary ring and a mating ring with gap maintaining means, such as spiral pumping grooves, formed in one of the rings which are shaped and dimensioned to pump the buffer gas through the first seal from the intermediate chamber into the process fluid chamber against the process fluid pressure and through the second seal from the intermediate chamber into the environment external to the housing and sealing area, thus avoiding the escape of the process fluid into the intermediate buffer chamber and thereby to the atmosphere. The inboard seal includes a first secondary sealing means disposed between one seal ring and the housing for sealing therebetween and a second secondary sealing means, disposed between the other seal ring and the shaft for sealing therebetween, the first and second secondary sealing means, which may comprise O-rings, each defining the boundary between the intermediate chamber and the process fluid chamber. The first and second secondary sealing means of the first rotary mechanical end face seal are sized and disposed to define radial walls in the back radial surfaces of each seal ring to thereby present essentially an equal area at an approximately identical radius, such that essentially the same mount of buffer fluid pressure acts on the back radial surfaces of each ring of the first rotary mechanical and face seal but in opposite directions and, on the process fluid side, the identical process fluid pressure acts on opposite sides of a portion of the respective rings of the first rotary mechanical end face seal essentially eliminating thrust forces acting on the first rotary mechanical end face seal.

Gas lubricated barrier seal

A double, back to back oriented mechanical end face seal for use in sealing toxic or corrosive fluids having an intermediate buffer fluid chamber into which a relatively inert gas, such as nitrogen, is provided for use as a buffer fluid. The nitrogen gas is maintained at a pressure which exceeds the process fluid pressure by at least 10 p.s.i. and, in a preferred embodiment, spiral pumping grooves in the mating rings of each of the seals are shaped and dimensioned to pump the nitrogen buffer gas through the first seal from the intermediate chamber into the process fluid chamber and through the second seal from the intermediate chamber into the environment external to the housing and sealing area, thereby avoiding the escape of the process fluid into the intermediate buffer chamber and to the atmosphere. Contamination of the process fluid by the buffer gas may be tolerated. The buffer gas may be any relatively inert gas, a gas which is non-hazardous to the environment and also is compatible with the process fluid used; appropriate examples are nitrogen, carbon dioxide, air or one of the noble gases. The seal can be used to seal a process fluid which is either a liquid or a gas.

Growing community of inventors

Park Ridge, IL, United States of America

Douglas J Volden