Lined Valves

The most commonly used valves in the chemical processing industries (CPI) are available with fluoropolymer lining. These are  

Fluoropol5miers serve two principal functions as lining for the body and the plug, ball, etc., and as part of the valve stem packing system. PTFE accounts for a large part of the use, although ETFE and ECTFE 

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For example a process flow scheme for crude oil stabilisation might contain details of equipment, lines, valves, controls and mass and heat balance information where appropriate. This would be the typical level of detail used in the project definition and preliminary design phase described in Section 12.0. 

If the boiler burns propane, natural gas, or fuel oil, then you ll need fluorocarbon o-rings on your fuel lines, valves, instrumentation and fittings. 

Log books, recipe sheets, batch sheets Identification of vessels, lines, valves etc. 

Spurious closure of both ecirc. line valves ) 3h-1 ](] X... 

Later as process and sometimes service lines, valves, controls and miscellaneous small accessories are added this extra space udll be needed to maintain an easily readable sheet. As this develops, attention should be... 

Injection moulding The injection moulder is a machine which first melts a thermoplastic and then injects that molten polymer into a mould. Such items as baskets, bowls, bins, telephones and electronic housings are produced by this technique. It can be used for lining valves. In this case the valve would be used as part of the mould. Very thick coatings are produced which give chemical resistance to the valve. At the same time, the metal valve housing will protect the valve from mechanical damage. 

A piping design feature that permits the expansion and contraction of lines to occur without risk of damage to the lines, valves, or other system components. 

It exploded spontaneously in a glass bomb closed with a PTFE-lined valve. No previous indications of instability had been noted dining distillation, pyrolysis or irradiation. 

Service lines decommissioned because of main renewals or other planned work shall be tested from the point of disconnection to the service line valve in the same manner as new service lines before reconnecting, except... 

Blowdown valves shall be provided so that each section of pipeline between main-line valves can be blown down to open atmosphere only. The sizes and capacity of the connections for blowing down the line... 

Valves used as service line valves shall meet the applicable requirements of para. PL-2.2.2. 

The use of soft seat service line valves is not recommended when the design of the valves is such that exposure to excessive heat could adversely affect the ability of the valve to prevent the flow of hydrogen gas. 

A valve incorporated in a meter bar that permits the meter to be bypassed does not qualify under this Code as a service line valve. 

Service line valves on service lines with pressure in excess of 60 psig, installed either inside buildings or in confined locations outside buildings where the blowing of gas would be hazardous, shall be designed and constructed to minimize the possibility of the removal of the core of the valve accidentally or willfully with ordinary household tools. 

The operating company shall make certain that the service line valves installed on high-pressure service lines are suitable for this use, either by making their own tests or by reviewing the tests made by the manufacturers. 

On service lines designed to operate at pressures in excess of 60 psig, the service line valves shall be the equivalent of a pressure lubricated valve or a needle type valve. Other types of valves may be used where tests by the manufacturer or by the user indicate that they are suitable for this kind of service. 

Service line valves shall be installed on all new service lines (including replacements) in a location readily accessible from the outside. 

Material flows, e.g. Failure of pumps/valves Incorrect operation of valves Plugging of lines/valves/fittings (especially air lines) Backflow from other equipment ... 

Consider adding a vapor line valve in place of a blind... 

Fig. 4.2-7. In-line safety- and side-stream valve (PN 2500, DN 60/32, adopted from BOHLER). 1, Tubular reactor train 2, In-line valve 3, Hydraulic actuator 4, Side outlet (inlet).

If the loss of circulation is due to damage or leakage inside the tower, one can restore flow by opening the start-up line (valve A shown in Fig. 5.2), and raising the liquid level, but if the reboiler is fouled, this will not help. 

Trap desorption. The choice of the thermal desorption apparatus is critical in order to avoid contamination and to be able to work with aroma compounds in a wide range of retention indices. In all systems, problems can be encountered due to reactive compounds or cold spots within the analyzer. It is recommended that all transfer lines, valves, or surfaces in contact with the volatile compounds be made of an inert material such as fused-silica or deactivated glass-lined stainless steel. Even more ideal are systems that do not have long... 

Several methods may be used to attach an NMR tube to a vacuum system. The O-ring union, illustrated in Fig. 8.5, permits attachment of standard NMR tubes to a vacuum outlet. Once the NMR tube has been filled with an air-sensitive sample on the vacuum system, it is necessary to bring the tube up to atmospheric pressure with inert gas, remove the tube, and quickly stopper it. Recently, a small in-line valve has been introduced which has a provision for an O-ring seal with a specially constructed NMR tube.22 This valve allows the NMR tube to be sealed before it is disconnected from the vacuum line, and the valve s left on the tube during data collection. Owing to its symmetric design, the valve does not interfere with the spinner. 

The in-line valve and associated NMR ntbc is manufactured by J. Young l.id., II Clovillc Road, Aclon, London W38BS, U K. In the United Stales one supplier is R. J. Brun(cldt Co., 1. O. Box 2066, Bartlesville, OK 74005. 

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