A mechanical seal assembly has two axially-spaced apart seals and including a rotary component that includes rotational members of each axially-spaced apart seal and a stationary component that includes stationary sealing members of each seal. A sleeve is located radially inwards of the rotational sealing members. An element, such as fluid ports, directs barrier or buffer fluid towards the sleeve and between the two axially-spaced apart seals. The sleeve is provided on its outer surface with means, such as recesses or protuberances, which displace barrier/buffer fluid axially towards both axially-spaced apart seals.

The present invention relates to a sealing system for a pump configured to pressurize a volatile liquid, such as liquid ammonia. The sealing system (2) includes a stuffing box (35) forming a barrier chamber (30) and a pump-side seal chamber (43), a mechanical seal (20) arranged in the barrier chamber (30), and a barrier-gas supply system (32) for supplying a barrier gas into the barrier chamber (30). The barrier gas has a pressure higher than a pressure of the volatile liquid in the pump-side seal chamber (43). The pump-side seal chamber (43) is located between an impeller (7) of the pump (1) and the mechanical seal (20). The barrier-gas supply system (32) includes a pressure control valve (50) configured to maintain a constant difference between pressure in the barrier chamber (30) and pressure in the pump-side seal chamber (43).

A shaft sealing arrangement includes a first seal and a second seal, wherein the first seal is designed in the form of a lip seal and the second seal is designed in the form of a mechanical seal. When the shaft is at a standstill, the lip seal performs the sealing action and, when the shaft is rotating, the mechanical seal performs the sealing action.

The invention relates to a mechanical seal arrangement comprising a first slide ring seal (2) having a rotating slide ring (21) and a stationary slide ring (22) defining a sealing gap (23) therebetween, a shaft sleeve (4), a driver (5) which connects the shaft sleeve (4) to the rotating slide ring (21) and which is arranged to transmit rotation of the shaft sleeve (4) to the rotating slide ring (21) a connecting arrangement (6) for connecting the shaft sleeve (4) to the driver (5), the connecting arrangement (6) comprising at least two rotary locks (60) and at least two recesses (40) in the shaft sleeve (4), wherein each of the rotary locks (60) has a bearing portion (61) and a locking portion (62), wherein the locking portion (62) laterally projects beyond the bearing portion (61), and wherein a rotational axis (Y-Y) of each rotary lock (60) is parallel to a central axis (X-X) of the shaft sleeve (4).

The invention relates to a pump assembly, especially of a mechanical seal assembly, for supplying a fluid, especially to a mechanical seal (2a, 2b), comprising exactly one drive (11) comprising a drive shaft (24), a first axial pump (21), which conveys the fluid in the axial direction (X-X) of the drive shaft, a second axial pump (22), which conveys the fluid in the axial direction of the drive shaft, and a radial pump (23), which conveys the fluid in the radial direction (R) of the drive shaft, wherein the first axial pump (21) and the second axial pump (22) are arranged in front of the radial pump (23) in the flow-through direction (B) of the fluid across the pump assembly, and wherein the drive (11) simultaneously drives the first axial pump (21), the second axial pump (22) and the radial pump (23).

A shaft sealing arrangement includes a first seal and a second seal, wherein the first seal is designed in the form of a lip seal and the second seal is designed in the form of a mechanical seal. When the shaft is at a standstill, the lip seal performs the sealing action and, when the shaft is rotating, the mechanical seal performs the sealing action.

An open cooling space or spiral cooling channel is formed between channel walls of a spool and an outer housing of a rotating shaft seal. The spool is sealed to the housing at the two ends thereof, does not intrude into the cooling inlet or outlet, and is axially removable and exchangeable without being distorted, thereby avoiding damage to the spool and/or contact between the spool and rotating seal elements. Due to the easy installation and removal of the spool, it can be installed as an upgrade after seal installation, and is easily cleaned and replaced. The cooling channel can be terminated by inlet and outlet rings, such that the spool does not require any rotational alignment within the seal assembly. The cooling channel can have a square or rectangular cross-section, thereby increasing thermal exchange between the cooling channel and the cooling channel spool rendering the cooling more efficient.

A mechanical seal assembly adapted for arrangement around a rotating shaft of a pump has first and second seals. Both include primary and mating rings, biasing mechanisms and annular flexible sealing membranes. The two seals can have different seal balances or different biasing forces (or both) to allow the second seal to run dry for extended periods.

An annular dual barrier seal includes a pair of axially extending inner seal lips and a pair of axially extending outer seal lips, the pair of inner seal lips are connected to the pair of outer seal lips by a radially outwardly extending web portion. The pair of inner seal lips extend axially by a first dimension and the pair of outer seal lips extend axially by a second dimension which is greater than the first dimension. The pair of inner seal lips have a sealing surface that is one of partially toroidal and partially elliptical and that engage the radially inwardly facing first sealing surface and the pair of outer seal lips have a sealing surface that is one of partially toroidal, partially elliptical and conical.

One or more techniques and/or systems are disclosed for mitigating fluid loss or leakage from a fluid pump with a rotating shaft driving a pumping mechanism. A packing gland component can have an internal seal formed by two dynamic O-rings that allows for use of lubricants at high pressures, as well as an outer seal for greater prevention of fluid loss. Further, the packing gland component can be a retrofit for existing packing gland components to provide for greater life and efficiency as compared to the existing packing gland components. Additionally, in some implementations, a sleeve may be fixedly attached to the rotating shaft between the packing gland and the shaft to provide a wear point for the packing gland.