Abstract: A monitoring seal system comprises a seal housing, a seal assembly, a temperature sensor and a controller. The seal assembly sealingly engages a rotary shaft to prevent fluid leakage between the shaft and the housing. The seal assembly has at least one seal. The seal has a primary ring and a mating ring. The temperature sensor senses the temperature in the vicinity of the seal. The controller determines whether an upset condition has occurred based on at least the temperature in the vicinity of the seal.

Abstract: A monitoring seal system comprises a seal housing, a seal assembly, a temperature sensor and a controller. The seal assembly sealingly engages a rotary shaft to prevent fluid leakage between the shaft and the housing. The seal assembly has at least one seal. The seal has a primary ring and a mating ring. The temperature sensor senses the temperature in the vicinity of the seal. The controller determines whether an upset condition has occurred based on at least the temperature in the vicinity of the seal.

Abstract: A contacting mechanical end face seal for use in applications having slow shaft rotational speeds, such as mixers, agitators and reactors, includes at least one seal ring having a face with spiral grooves. Both hydrostatic and hydrodynamic lift characteristics in the seal are utilized to generate and maintain a seal gap having sufficient stiffness to prevent contact of the seal ring faces during operation. Specific characteristics, or combinations of them, include a land to groove ratio between 0.2-0.9, tapered groove surfaces which are inclined from the O.D. toward the dam, groove area to land area ratios greater than 1.5, a stepped groove having a greater depth at the O.D. relative to the depth adjacent the dam, alternating deep and shallow grooves, and groove area to dam area ratio in the interface greater than 1.2.

Abstract: Improved spiral grooves in a mechanical face seal have plural terminal corners which more evenly distribute the fluid pressure generated within the seal gap into discrete pressure zones which are radially displaced and may also be circumferentially displaced from the other pressure zones generated by the same groove. Alternative embodiments include grooves having surfaces of varying depths wherein each of the plural terminal groove corners is associated with a section of the groove having a surface at a particular depth.

Abstract: A seal face of at least one ring used in a non-contacting, gap-type mechanical end face seal having a pattern including an optional dam and an annular grooved area. The annular grooved area has one of several embodiments, including entrance lands which are essentially triangular and have one side contiguous with one circumferential edge of the annular grooved area. These embodiments further include a set of converging boundary sides of the groove to provide a pressure zone effect. Seal face patterns include a contiguous groove around the circumference of the seal face and a series of annular bands comprising a repeating pattern of an essentially triangular groove interposed between two adjacent, but oppositely oriented, lands.

Abstract: Improved spiral grooves in a mechanical face seal have plural terminal corners which more evenly distribute the fluid pressure generated within the seal gap into discrete pressure zones which are radially displaced and may also be circumferentially displaced from the other pressure zones generated by the same groove. Alternative embodiments include grooves having surfaces of varying depths wherein each of the plural terminal groove corners is associated with a section of the groove having a surface at a particular depth.

Abstract: A seal system for sealing a housing and rotatable shaft against leakage of a gas under high pressure; hydrogen is an example. The system, using multiple seals in tandem, provides a stepped reduction of high pressure gas at full height pressure to a low pressure across the individual seal modules.The seal system has plural, axially spaced spiral-grooved end face seal modules mounted between the shaft and housing, the axial spaces between the seals defining a chamber. Each seal module has a primary seal ring affixed to the housing and a mating ring affixed for rotation with the shaft, the two rings having opposed, radially extending faces; each mating ring has a plurality of radial spiral grooves extending radially inward from the outer diameter or circumference.

Abstract: A secondary seal for use in a high temperature environment, including only non-elastomeric elements, includes split high temperature carbon graphite secondary seal rings axially biased by a first set of springs and radially biased by a second set of springs.

Abstract: A seal face of a ring used in a non-contacting, gap-type seal having an annular groove area with microdams, each having a preferable width of about 0.025 inches, between a plurality of groove surface areas. The microdams provide a boundary to the groove surface areas whereby the recess of each groove surface area bounded by the microdams acts as a unitary pressure zone and the pressure in the separate zones decreases in a series of steps as measured from one circumference of the ring to the other circumference.

Abstract: A seal system is disclosed for sealing a housing and rotatable shaft against leakage of high vapor-pressure liquids such as natural gas. The method of sealing comtemplates phase change of the liquefied hydrocarbon fluid across a first module. The gas so formed is contained by a second seal module which operates as a dry running gas seal. The seal system has plural, axially spaced spiral-groove seal modules mounted between the shaft and housing. Each seal module has a primary ring affixed to the housing and a mating ring affixed for rotation with the shaft and the modules define an intermediate cavity. The rings have opposed, radially extending faces, one of which has a plurality of downstream pumping spiral grooves extending from one circumference. The grooves of the grooved ring of the upstream module have a pattern which upon shaft rotation creates shear heating of the liquefied hydrocarbon fluid.

Abstract: A seal system is disclosed for sealing a housing and rotatable shaft against leakage of high vapor-pressure liquids. The method of sealing contemplates phase change of the liquefied hydrocarbon fluid across a first module. The gas so formed is contained by a second seal module which operates as a dry running gas seal. The seal system has plural, axially spaced spiral-groove seal modules mounted between the shaft and housing. Each seal module has a primary ring affixed to the housing and a mating ring affixed for rotation with the shaft and the modules define an intermediate cavity. The rings have opposed, radially extending faces, one of which has a plurality of downstream pumping spiral grooves extending from one circumference. The grooves of the grooved ring of the upstream module are of a depth not to exceed about 100 micro-inches. In a preferred form, the depth of the grooves of the upstream module do not exceed 50 micro-inches.