Spool pieces

Fig. 13. (a) Preferential flow through rotary valve and (b) correction from installation of a vertical spool piece. 

Since a spool piece in the inlet piping is required for maintenance reasons, it is recommended that this be replaced by a flow measuring section containing the required instrumentation. 

Four separate pressure gauges read at expander inlet, taps located about one pipe diameter from expander flanges located in spool piece, 90° apart. 

Feed inlet and overflow connections are elastomer lined spool-piece adapters. 

Aluminum Pipe) A Heavy Wall Alclad Aluminum "Spool Piece" Will Avoid Galvanic Corrosion of Pipe... 

This section includes any special tools or equipment that the procedure user must have in order to perform the procedure. This prevents the procedure users from completing half of a procedure and then finding out that they need a tool to finish. The section can include personal protective equipment such as respirators, tools such as a micrometer, or objects such as spool pieces or chemicals. 

Figure 10.36 shows the infrared spectra of the liner. It matches the spectra of pol5winylidene fluoride which is a partially fluorinated fluoropol5mier and is susceptible to chemical attack by HF. DSC analysis measured a melting temperature of 165°C for the liner sample. Follow-up discussions with the plant personnel revealed that the wrong spool piece had been installed instead of a PTFE-lined pipe. 

The piping arrangement should also provide access for tube removal. This usually means a spool piece or flanged elbow in the pipe line connecting to the top of the channel nozzle. 

By providing easily removable spool pieces, flanged elbows, break flanges, or short pipe runs to provide adequate clearances for tube removal equipment,... 

In Figure 7-86, four typical piping arrangements are shown for installing thermowells. When the enlarged sections must be provided with a 2-1/2-inch spool piece, the minimum length should be at least 12 inches. Note that the Figure 7-86 details are accessible so the thermowells can be taken out... 

In Figure 7-86c, two 2-1/2-inch pipe elbows are installed together with a pipe spool piece at the lower end to increase its len h for the installation of a thermowell with a thermobulb. The other elbow adapter holds a dial thermometer in a 6-inch long thermowell. In Figure 7-86d, a single 2-1/2-inch pipe elbow is installed with suitable pipe reducers to fit the small size process line. The 1-inch elbow adapter holds a 6-inch-long well with a thermocouple (T/C). The T/C head is connected with an electrical conduit that carries the circuit to the temperature recorder on the control panel. 

In Figure 7-99 the 2-1/2-inch welding pipe elbows are used for swaging-up a section of the piping. This applies to 3/4-inch to 2-inch process line thermowells. By installing a pipe spool piece between the pipe elbows and welding 1-inch elbow adapters on both elbows, two temperature instruments can be handled for the same service. 

Reactor refueling systems. A series of systems associated with the reactor and reactor vessel are required for refueling. Outside the reactor vessel these include three fuel transfer ports, eight test position spool pieces, two floor valve ad ters and the test transfer port, and the reactor containment building cranes. Inside the reactor vessel are three in-vessel handling machines (IVHMs) and three invessel storage modules. Three IVHMs are required because of the mission of the FFTF that requires closed test loops in the reactor core which interfere with direct access to die entire core with one machine. 

At this stage, sensitive instruments and control valves may be absent from the system, in order to prevent damage from any debris flushed through pipework, and replaced by temporary spool pieces. Strainers should be fitted to the suction lines of pumps and certain compressors. Orifice plates should be omitted. 

There is a diverse emergency shut down system which is initiated manually if it is not possible to insert the control rods. It allows for injection of boron into the reactor. Since inadvertent operation of this system must be completely prevented, it requires insertion of a spool piece to connect the boron tank to the reactor. The negative moderator temperature coefficient is sufficient to maintain the reactor in a hot shut down condition for several days until the spool piece can be inserted. 

Maintenance located a 12 in. 300 psi RF check valve that was used on firewater pumps, but not on hydrocarbons. This substitute valve was manufactured to a Japanese flange to flange standard dimensioa The Japanese standard face to face dimensions are more compact than the ANSI standard so the storeroom stocked this valve with a connecting short spool piece of 12 in. piping (see Fig. 2.27 to imderstand the dimension). 

Unfortunately maintenance personnel had not been aware of the missing piece of information and endorsed the incorrect valve as replacement in kind. The flanges between check valve and the spool piece had a rubber gasket suitable for fire-water services, but not for hot hydrocarbons. 

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