The two most common forms of industrial seal are mechanical seals and braided packing seals. Braided packing seals have been around since 3,000 B.C. when hemp was used to tackle sealing bamboo piping structures in the Far East. As time passed, cotton and jute were adapted by various cultures and became widely used in India and China, eventually making their way to Europe and the rest of the world. Modern braided packing seals come in a wide variety of designs and use a range of different materials, including compound designs utilizing different materials and design formats, including coils and spirals.

Industrial seals are used to handle leaks caused by joint spacing. One fundamental feature of seal packing is the ability of the seal to ‘flow’ into the joint spaces and effectively block them off to whatever is passing through the pipe system. External pressure is used to counteract the fluid pressure inside the pipe, however these types of seals do not stop all leaks; they simply reduce the level of leakage to an acceptable level of loss.

How you select a suitable packing seal will be by reference to the characteristics of the material used in making the seal. How capable is the material in maintaining an effective seal within the joint? How effective is seal integrity maintained under the pressures within the system it is used? Can it handle rotating pressure caused by dynamic rotation of a shaft within the piping system? How resistant is the seal material to the eroding or corrosive action of the fluid being handled? Is there any danger of the seal material causing contamination within the fluid being handled?

‘Durameter’ or hardness of the seal packing material is the measure used to gauge how well the packing material will flow under compression force. Most industrial seals have a durameter value between 35 and 95, with lower ratings indicating a softer material. Softer materials are more easily applied to the joint space as they require less compression force to be effective. However, seal materials with low durameter values are less rigid and are not as strong as higher rated materials. On the other end of the scale, high durameter seal materials do provide high strength and rigidity characteristics, however they are more difficult to deploy because they do require additional compression force to be applied in order to make the seal material flow into the joint space. For these reasons, most typical industrial packing seal materials are rated at the higher end of the scale (typically between 60 and 90 durameters).

Braided packing seal designs usually require a cooling source (typically water but not always), which acts as to lubricate and maintain optimal temperatures due to the build-up of heat from compression forces. If the seal is not sufficiently cooled, the seal may fail due heat build-up affecting the integrity of the material or the seal itself. This raises the issue of water consumption in pump design; for instance a 3 foot shaft, which is fairly typical within a modern process pump, will require somewhere between 3 and 5 gallons per minute for cooling purposes. This equates to approximately 1.5 million gallons per annum for cooling purposes alone, and with many countries and regions suffering from water shortages, or imposing restrictions on water consumption as well as the potential cost implications, the use of an industrial seal has much greater implications for pump design than you may initially think.

Author Bio: Lawrence Reaves writes about industrial pumps and other fluid handling equipment. To learn more about pumping services, visit Colfax Corporation at: ColfaxCorp.com .

Category: Business
Keywords: braided packing industrial seals, braided seals, packing seals, braided packing industrial seal