Threaded connection gasket

The finite element simulations were performed using the DNF constitutive model presented in Sec. 

This model allows for direct simulations of the viscoplastic flow and temperature behavior of the hose in the different loading scenarios. Material parameters for the DNF model were obtained from the literature and the tension tests described above. 

One representative figure illustrating the results obtained from the FE simulations is shown in Fig. 

A comparison of the predicted stresses from the FE analysis with the experimentally determined strength of the PTFE liner showed that the failure of the liner was to be expected. Even if the temperature of the liner was 20°C, the combination of internal pressure and axial load could have caused the axial split in the PTFE liner that was observed. 

This analysis was straightforward. The greatest effort was in determining the material parameters for the DNF model, but sufficient literature was available on PTFE to reduce the number of tests to simple tensile and multiple temperatures. The following example provides a more detailed analysis where more material testing was needed to explain the performance of a fluoropolymer gasket. 

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Occasionally, check from the sterile side of the filter for leaks at the gaskets, valves, piping, threaded connection, etc. Also, check the spargers in the tank for debris or pockets. Make sure filters are dried out before being placed in actual service. 

Figure 11.26 Contours of Mises stress of the threaded connection and PTFE gasket.

The employer shall ensure that all wiring components and utilization equipment in hazardous locations are maintained in a dust-tight, dust-ignition-proof, or explosion-proof condition, as appropriate. There shall be no loose or missing screws, gaskets, threaded connections, seals, or other impairments to a tight condition. 

Fittings. Fittings connect pipes and provide for the attachment of equipment to change flow direction. They must be easily cleaned inside and out, have no exposed pipe threads, and, if of the detachable type, have an appropriate gasket. The fittings are constmcted of the same or similar materials as the pipeline and are installed on tubing. Standard shapes and sizes are specified by the 3A Standards Committee. 

The connections were not made correctly. In particular, screwed joints were secured by only a few threads, different threads were combined, or gaskets were missing. 

Bag filters are perhaps the most widely used of these types of pretreatment equipment, and they are also commonly employed (and highly recommended) for sidestream application in HW boiler circuits. They are reliable and robust and tend to be available in an almost infinite number of permutations. When sizing, specification items to be considered include flow rates, vessel materials, housing and support-basket sizes, pipe sizes, connection threads and flanges, outlet positions, code and pressure ratings, gasket materials, bag shapes, bag materials, and micron ratings. 

If specified, cylindrical threads conforming to ISO 228, Fart 1 may be used. If cylindrical threads are used, they shall be sealed with a contained face gasket, and the connection boss shall have a machined face suitable for gasket containment (see Figure 2-1). 

Fig. 10.1. Some common high-pressure tank fittings. The seal in the top three fittings is made by contact between the nipple in the connection and the seat in the outlet. Note the cone-shaped, round, and bullet-shaped nipples for (a), (b), and (c) respectively. The bottom connection (d) is sealed by means of a flat soft-metal gasket. Never attempt to mix outlet and connections between the various designs. Note the grooves on the connection nuts for connections (b), (c), and (d). This groove indicates a fitting with left-handed threads. (Reproduced by permission of the copyright holder, Mathe-son Gas Products, Inc.)...

Figure 5.1 Disassembled view of the spectroelectrochemical cell. (1) Tightening brass cap (threaded inside). (2) Brass ring required to tighten the cell. (3) Working electrode (brass rod with platinum soldered to the base). (4) Auxiliary electrode platinum wire with the tip made flush to the teflon base of the cell. (5) Pseudoreference electrode silver wire, also made flush to the teflon. (6,7) Luer-lock-type injection ports. (8) Cell body, top part aluminium, lower part teflon. (All three electrodes and both filling ports are press fitted into the cell body, so that they can be replaced if needed.) (9) Teflon spacer, determines the pathlength of the cell and masks the reference and counter electrodes from the incident beam. (10) Calcium fluoride window (Wilmad, standard 38.5 x 19.5 x 4mm). (11) Rubber gasket. (12) Hollow brass cell body with threaded inlet and outlet ports (Swagelock) for connection to circulating bath. (13) Two-mirror reflectance accessory (Thermo-SpectraTech FT-30). (14,15) Mirrors.

Pipes with screwed connections should not be used due to the chances of leaks from threads. Flanged connections with PTFE or acid resistant compressed asbestos (where permitted) gaskets give better service life. 

Teflon Mape should never be used on cylinder connections or tube-fitting connections. Use Teflon tape only on pipe threads where the seal is made at the threads. All other connections have metal to metal face seals or gasket seals. 

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