The _____ form the connection for the attachment of the boiler steam generating tubes to the drum and the saturated steam outlet tubes from the top or steam space of the drum.
A ) tubes
B ) welding
C ) stubs
D ) manholes
Answer: C
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3rd Class B1
- Only some of the firetubes in firetube boilers are:
- Boiler tubes may be fabricated in a _________ form, or they may be welded.
- To form a drum or shell of the required diameter, the plates must be rolled to the correct _________.
- Boiler tubes are sometimes welded to _____, which have already been welded to the headers or drum.
- Directly after rolling and while the tube is still hot, a reeling machine shown in Fig. 14 smooths the outer surface. This is called __________.
- _______ boilers must be built or put together in the field (field erected).
- In the field, the stress relieving of welded pipe joints may be accomplished by means of __________ induction coils, which are wrapped around the welded section of the pipe.
- The ASME Code Section __ specifies that the size of an elliptical manhole shall not be less than 280 mm by 380 mm or 250 mm by 410 mm.
- Postweld heat treatment, often called stressrelieving, consists of heating the welded parts uniformly, to a temperature sufficient to relieve most of the stresses created by the heat from the welding. The parts are then cooled at a constant rate.
- Drum manhole openings may be elliptical or _____.
- The gaskets used are the woven type for pressures up to _____ kPa and the metallic type for higher pressures.
- The drum is used as the major anchor point for other boiler components, and for this reason, accurate location is important.
- Coal pulverizers must be installed _____ to allow installation of coal piping to the boiler.
- The _________ steel carries the weight of the steam drum and the major pressure components.
- Large quantities of ______ are used to complete the foundations, which must support the loads from the boiler and all of the auxiliary equipment.
- The covers fit on the ______ of the drum and are held in place by means of bolts and yoke pieces.
- The boiler tubes themselves are used to support the top _____ in a bottom-supported boiler.
- The use of a membrane or water-cooled walls has reduced the use of __________ in modern water tube boilers.
- Tubes for boiler application are either hot-finished, or _____ -drawn depending on the size, tolerance, and finish desired.
- Another method used to produce seamless tubes is known as ________.
- Nozzles and stubs for connecting the drum to tubes and piping are formed by _____ forging from a solid steel cylinder, or "billet".
- Upon completion of the structural steel installation, the "U" shaped hangers are attached to the structural steel for support of the main steam ______.
- A final test which is carried out in the manufacturer's shop is a hydraulic or hydrostatic test, (conducted according to the ASME Code Section I, PW-54), at a pressure of ____ times the design pressure.
- What is meant by the foundation of a boiler?
- For pressures up to ______ and temperatures up to 454°C, handhole covers with gaskets are used and are bolted into place.