Joints pressure-seal

The movement-absorbing devices used in semirigid and nonrigid piping systems are usually called expansion joints. Based on the method by which the pressure seal is effected, joints are either of the packed type or the packless or bellows type. Selection depends not only on the required movement but also on the severity of service in terms of pressure and temperature, tolerabiUty of leakage, and the number of service cycles. 

Pressure-seal joints (Fig. 10-142) are used for pressures of 4.4 MPa (600 Ibf/in") and higher. They use less metal than flanged joints but require much more machining of surfaces. There are several designs, in all of which increasing fluid pressure increases the... 

Type S is a floating head type. As the tubes heat up, they expand. As they expand, the floating head moves back and forth, but the pressure seal is not at the sliding joint. The pressure seal is at the fixed shell Joint in the outer head, which contains the pressure. The floating head floats free inside the pressure vessel as the tubes move. Types P and W are floating heads where the movement of the head effects the seal between either the shell-side or tube-side fluid and atmosphere. 

The next type of joint is weld overlays, which are often utilized to eliminate the need for costly thrust blocks [Fig. 4-2(p)]. In designing the pipe an analysis was made to ensure that it possessed sufficient longitudinal strength. It makes sense, then, to make the weld joints be at least as strong as the longitudinal strength of the pipe rather than just as an internal pressure-seal pipe. 

ISO 3603 1977 Fittings for unplasticized polyvinyl chloride (PVC) pressure pipes with elastic sealing ring type joints - Pressure test for leakproofness ISO 3604 1976 Fittings for unplasticized polyvinyl chloride (PVC) pressure pipes with elastic sealing ring type joints - Pressure test for leakproofness under conditions of external hydraulic pressure... 

Photolysis Reactors and Ultraviolet Sources. For 253.7-m/ irradiation, a modified irradiation apparatus purchased from Delmar Co. was used. The reactor was a 2-necked, 500-ml., round-bottomed flask. One neck was an O-ring joint, and the other was a 24/40 joint. A 4- X 1-inch coiled low pressure mercury quartz lamp was placed inside the flask through the O-ring neck, and the joint was sealed with removable O-rings. The reactor was connected directly to the mass spectrometer by the 24/40 joint. The samples were placed inside the flask and irradiated internally. The O-ring was shielded from direct radiation so as not to induce degradation. The estimated output of the lamp was 30 watts, and the ambient temperature within the reactor during irradiation was 70°C. 

One of the most applied high-pressure standards for the piping components is based on the so--called IG-Standard, which was established by an association of the German Chemical Industry beginning with 1930. Similar developments took place in the US and elsewhere. The pipes applied are of seamless design. The joints and seals which have been approved for high-pressure are shown in Fig. 4.2-1. 

The presence of oil in boiler water is intolerable, as it causes foaming and cany-over. Steps should be taken to prevent its entiy into the boiler through the feedwater system or leakage through pressure seals and joints. Organic antifoaming agents are a recent development with some successful application. However, their use should not be considered a cure-all. 

Check that all joints are sealed and that the water pump is producing a vacuum it will change note as the vacuum is produced, when it is working properly. If there is no vacuum, the solution may not boil and you will overheat it in trying to promote evaporation. The joints may suddenly seal and the solution will then boil vigorously under the reduced pressure and will bump into the condenser and receiving flask. 

An autoclave is a thick-walled vessel, usually made of steel, which allows us to carry out reactions under pressure and at high temperatures. (The original definition implied a self-closing vessel with internal pressure sealing its joints the closure is now made externally.)... 

Strong and clean structural, hermetic, and high-pressure seals can be obtained from this process. Important determinants of bond quality in induction welding are the joint design and induction coil design. With automatic equipment, welds can be made in less than 1 s. 

ISO 3603 1977 Fittings for unplasticised polyvinyl chloride (uPVC) pressure pipes with elastic sealing ring type joints - Pressure test for leakproofness. 

Vacuum molding n. This type of molding is used to mold fiberglass-reinforced plastics. The method allows molding without high temperatures and pressures. In this technique, layers of reinforced media are applied to the mold by hand. Resin is either sprayed or brushed on after each layer is positioned. The flexible sheet (usually cellophane or polyvinyl acetate) is placed over the lay up. Joints and seals are sealed and a vacuum causes the b to collapse over the face of the product not contacting the mold. The resultant pressure tends to eliminate voids and forces out any excess resin or entrapped air. Madox DM (1998) Handbook of physical vapor deposition (PVD) processing. Noyes Data Corporation, New York. 

A container is no stronger than its weakest member, such as a joint, cover, seal, wall, or relief device. Corrosion or physical damage from handling may create a weak point. Containers that have pressurized contents may reach pressures too high for the container or any of its parts. Evenmally, a container may leak slowly or rupture suddenly. An example is the explosive release of an air bag during installation or maintenance. 

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