The sealing rings are in four parts and pressed together around the piston rods by means of _____

A．nuts

B．bolts

C．coil springs

D．stuffing boxes

[单选题]The sealing rings are in four parts and pressed together around the piston rods by means of （）.A . nutsB . boltsC . coil springsD . stuffing boxe

[单选题]The bearing of tailshaft sealing equipment which adopts the oil nature circulation is hot, the reason isA．the rotate speed fluctuationB．the ventilation tube cloggedC．the main engine accelerate so fastD．stormy waves

[单选题]Sealing in pump shaft is achieved by means of the ( ).A．gasketB．packingC．o-ring

[单选题]The piston rings are manufactured with a diameter （） the bore of the cylinder.A . larger thanB . smaller thanC . equal toD . none of the above

[单选题]The piston rings if found worn out （） and supplied by shipchandler.A . must replaceB . must to be equippedC . has to be repairedD . have to be renewed

[单选题]The film of oil between the rings and the liner is not only essential for the lubrication but also plays an important part in achieving （）.A . an oil sealB . removing heatC . a gas sealD . cooling the pisto

[单选题]Among the rings of a piston the （） one is subjected to the greatest load and temperature.A . bottomB . middleC . topD . none of the above

[单选题]All the rings are slightly rounded on their external top and bottom edges to keep the oil film on the cylinder liner during （） for new piston rings.A . the running-in periodB . the running processC . gas exchange processD . the boiler firing

[单选题]These piston rings are so badly worn that they must be （）.A . renewedB . weldedC . machinedD . chromium-plated

[单选题]Cast iron carrier rings, （） machined grooves, are provided for all the pistons.A . caulked intoB . caulking intoC . pressed intoD . screwed into