【正文】 ked D. scaled 1135 The internal part of boiler should be welded by yard if found _____ 鍋爐內(nèi)側(cè)發(fā)現(xiàn)裂紋，應(yīng)電焊修理。 A. reduce B. rise C. raise D. fall 1126 C 1127 A 1128 D 1129 B 1130 Which of the following will be the advantage of a centrifugal pump as pared with a reciprocating pump? ① Its discharge is continuous。 ③ . they will develop a discharged pressure equal to the resistance to be overe, irrespective of speed. 容積式泵正常工作時具有以下特性：排量幾乎與轉(zhuǎn)速成正比；具有自吸能力；不管速 度如何，都能產(chǎn)生大小等于需克服阻力的排出壓力。 ③ centrifugal. 噴射泵和螺桿泵都具有干吸能力，而離心泵沒有。 A. injector B. positive displacement C. centrifugal D. centripetal 1115 What is the purpose of a relief valve? 釋放閥可用來當(dāng)排出閥關(guān)閉時將液體回流到吸人側(cè)。 A. draw the liquid in/force the liquid out B. force the liquid out / draw the liquid in C. suction/draw D. deliver/outlet 1109 Throttling in the ______ line of a centrifugal pump involves the risk of the pump ，節(jié)流吸人管路，會產(chǎn)生氣蝕危險。 A. kiic/pressure B. kiic/essential C. pressure/kiic D. pressure/height 1103 The amount of fluid delivered by a centrifugal pump can be regulated by _______ 離心泵的排隊量可通過改變壓力來調(diào)節(jié)，出可通過改變轉(zhuǎn)子的速度調(diào)節(jié)。 A. depending on B. in relative to C. regardless of D. because of 1090 B 1091 A 1092 A 1093 C 1094 C 1095 A gear pump belongs to _______ according to its working principle. 根據(jù)工作原理，齒輪泵屬于容積式泵。 A. positive displacement B. ejector C. centrifugal D. air pressor 1092 A monopump is a singlescrew pump. That means it consists of _______ rotor(s). 單螺桿泵只有一個轉(zhuǎn)子。 C. triple screw pump D. centripetal pump 1100 A Screw pump belongs to _______ according to its working principle. 根據(jù)工作原理，螺桿泵屬于容積式泵。 ③ centrifugal. 往復(fù)泵和旋渦泵都具有干吸能力，而離心泵沒有。 A. ① only B. ② only C. ① and ② D. ① ② and ③ l l 12 Shaft sealing in a centrifugal pump can be effected by _______ 離心泵的軸封可用機(jī)械密封，也可用填料箱。 A. centrifugal B. plunger C. injector D. water 1120 Which of the following pumps are selfpriming, and can deal with liquid from a level below the pump。 ③ . screw. 齒輪泵和螺桿泵都是容積式泵，排出閥關(guān)閉’將會產(chǎn)生具有破壞性的壓力，而離心泵不會。 A. slack enough to allow slight leakage of fluid B. slightly clocked C. brought up tight so as not to allow any leakage D. fitted with a relief valve 1128 Air chambers are usually fitted to reciprocating pumps in order to ______ 往復(fù)泵中的空氣室用來保持流量穩(wěn)定。 ③ gear. ① ② ③ A. ① only B. ① and ② C. ② ③ and ③ D. ① ② and ③ 往復(fù)泵、齒輪泵和葉片泵都具有干吸能力。 A. Safety valves B. Water tube C. Steam stop valves D. Blow down valves 1140 The furnace of a oil fired boiler should be _____ before the operating burner is lit. 鍋爐點火前，應(yīng)進(jìn)行掃氣。 1147 Safety valves on a boiler vent to the _____鍋爐安全閥通大氣。 A. latent heat of condensation B. latent heat of vaporization C. latent heat of saturation D. sensible heat of condensation 1151 C 1152 B 1153 D 1154 A 1155 A 1156As for an oilfired boiler if at a normal steaming condition and water goes out of sight in gauge glasses the action you should take is: ① secure oil to fires。這是因為鍋爐水是水和汽 泡的混合物 (水位表本身上端通汽下端通水 )，向鍋爐供水后，等汽泡凝結(jié)，水位反而下降。 A. Boiler B. Incinerator C. Oily water separator D. Sewage treatment unit 1161 D 1162 D 1163 B 1164 A 1165 C 1166 Oil water separators are used to ensure that ships don39。 A. center B. periphery C. inlet D. upper parts 1172 For many years marine centrifuges were designed for _____ operation, that is the machines were run for a period during which solids accumulated in the bowl. The machine was stopped when the accumulated solids began to impair its performance. 很多年以來，離心式分油機(jī)被設(shè)計成分批運(yùn)行。 A. an electric motor B. a diesel engine C. a pressor D. oil 1179 In a hydraulic system , _____ are used to protect the system from over pressure. 在液壓系統(tǒng)中，安全閥用來防止系統(tǒng)超壓。 A. The hydraulic pumps B. Valves C. Hydraulic cylinders D. Hydraulic motors l 187 Among the basic categories of equipment, which of the following is used to convert hydraulic energy into continuous rotary motion.? 在液壓系統(tǒng)中，液壓馬達(dá)將液壓能轉(zhuǎn)變?yōu)槌掷m(xù)的回轉(zhuǎn)運(yùn)動。當(dāng)驅(qū)動壓力釋放后，負(fù)荷將會引起柱塞桿收進(jìn)。 A. Hydraulic oil B. Animal oil C. Light oil D. Fuel oil 1202 _____ is the production of pure water from sea water by evaporation and recondensing 通過蒸發(fā)和再冷凝，由海水產(chǎn)生淡水的過程稱為“蒸餾”。 A. the slewing motor B. the luffing motor C. the hoisting motor D. none of the above 1196 The crane is usually mounted on a pedestal to offer adequate _____ to the operator. 回轉(zhuǎn)式起貨機(jī) (克令吊 )一般安裝在平臺上，確保向操作者提供足夠的視野。 A. Relief valves B. Check valves C. Safety valves D. Reducing valve 1189 The rotor of the hydraulic motor rotates at a speed proportional to the _____ 液壓馬達(dá)轉(zhuǎn)子的回轉(zhuǎn)速度與油量有關(guān)，而與油壓無關(guān)。 A. Cranes B. Mooring winches C. Windlasses D. Foreman 1176 B 1177 A 1178 D 1179 C 1180 A 1181 Among the basic categories of equipment, which of the following are used to allow the hydraulic energy to be controlled?在液壓系統(tǒng)中，液壓閥可實現(xiàn)對液壓能的控制。 A. purifying B. batch C. long period D. temporary 1173 For a purifier, changing to a gravity disc with larger hole diameter will move the