German coax seals coax models coax prices

coax seals are devices that prevent fluid leakage, consisting of at least one pair of faces perpendicular to the rotation axis that remain in contact and slide relative to each other under the action of fluid pressure and the elastic force (or magnetic force) of a compensation mechanism, along with auxiliary seals. Mechanical seals where the elastic loading mechanism and auxiliary seal are metal bellows are called metal bellows seals. In light-duty seals, rubber bellows are also used as auxiliary seals; since the elastic force of rubber bellows is limited, springs are generally required to supplement the loading force. Mechanical seals are commonly referred to as "mechanical seals".

coax seal classification

1) Packing seal: The packing seal has a simple structure, low price, and is easy to maintain. However, it has high leakage and high power loss. Therefore, packing seals are used for transporting general media, such as water; they are generally not suitable for petroleum and chemical media, especially valuable, flammable, explosive, or toxic media. 2) Mechanical seal: Mechanical seals (also known as face seals) offer good sealing performance, very low leakage, and long service life, but are expensive and have higher requirements for machining, installation, maintenance, and repair compared to general seals. Mechanical seals are suitable for transporting petroleum and chemical media and can be used for media with various viscosities, strong corrosiveness, and containing particles. The American Petroleum Institute standard API610 (8rd edition) stipulates: Unless otherwise specified by the user, cartridge mechanical seals shall be installed. 3) Dynamic seal: Dynamic seals can be divided into back-vane seals and auxiliary impeller seals. During pump operation, the centrifugal force of the back vanes (or auxiliary impeller) reduces the medium pressure at the shaft seal to atmospheric or negative pressure, preventing leakage during use. When stopped, the centrifugal force disappears, and the sealing effect of the back vanes (or auxiliary impeller) fails; at this time, the stop-seal device provides sealing. Packing seals are commonly used in stop-seal devices paired with back-vane (or auxiliary impeller) seals. There are two types of packing seals: standard and mechanically adjustable. Standard packing seals are similar to those in general packing seal pumps, requiring slight positive pressure at the shaft seal to avoid dry friction of the packing. Mechanically adjustable packing seals use counterweights to loosen the packing during pump operation and tighten it when stopped. Dynamic seals are reliable, inexpensive, and easy to maintain, suitable for transporting media with many solid particles, such as slurry pumps and feed slurry pumps in the phosphate industry. The disadvantages are higher power loss compared to mechanical seals and shorter service life of the stop-seal device. The seal between the rotating pump shaft and the stationary pump casing is called the shaft seal. Its function is to prevent high-pressure liquid from leaking out of the pump along the shaft or outside air from entering along the shaft. For centrifugal pumps, the shaft seal is a dynamic seal. Depending on whether the sealing surfaces are in contact, it can be divided into contact dynamic seals and non-contact dynamic seals. In contact dynamic seals, the sealing device contacts the shaft, and there is relative friction between them. Contact dynamic seals include packing seals and mechanical seals.

coax seal operation

1) If slight leakage occurs after the pump starts, observe for a period of time. If the leakage does not decrease after continuous operation for 4 hours, stop the pump for inspection. 2) The pump operating pressure should be stable, with pressure fluctuations not exceeding 1 kg/cm². 3) During pump operation, avoid cavitation to prevent dry friction and damage to the sealing surfaces. 3) Check the sealing condition regularly. During operation, if leakage exceeds the standard (not more than 5 drops/min for heavy oil, not more than 10 drops/min for light oil), and there is no improvement within 2-3 days, stop the pump to inspect the sealing device.

coax seal maintenance

1) Control of shaft seal pressure: High shaft seal pressure can cause steam leakage from the shaft seal, easily leading to water ingress into the oil and deterioration of turbine oil quality. Excessively high shaft seal pressure will trigger the safety valve of the equalizing tank, wasting working fluid and damaging equipment. Too low shaft seal pressure may cause a drop in unit vacuum, allowing cold air to enter the shaft seal or even the cylinder, causing cooling of the shaft seal section or inside the cylinder, seriously threatening equipment safety. 2) Impact of abnormal shaft seal temperature on the unit: When the shaft seal temperature is too high, especially before unit startup, excessive heat causes intense heating at the shaft end gland and rotor gland section, leading to local stress concentration and certain deformation. This may change the clearance between the rotor and cylinder, increase shaft seal steam leakage and differential expansion, and potentially cause rubbing between stationary and rotating parts. When the shaft seal temperature is too low, the shaft end gland and rotor gland section are cooled, also causing local stress concentration, changing the clearance between the cylinder and rotor, increasing shaft end steam leakage, and reducing differential expansion. Low shaft seal temperature may also cause water carryover in the shaft seal supply steam, leading to water hammer in the supply pipeline. In severe cases, this can cause water ingress into the turbine.

Weidou Intelligent Technology specializes in selling German coax seals, coax O-rings, coax sealing strips, coax pipe seals, coax cable seals, coax rubber seals, coax mechanical seals, coax gaskets, coax oil seals, coax shaft seals, coax metal seals, coax high-pressure seals, coax spiral seals, coax centrifugal seals, coax sealing rings, coax original German imports. Welcome customers to inquire and order.