（一）汽轮机螺栓电加热器应符合下列要求：
(1) The bolt electric heater of a steam turbine shall meet the following requirements:
1、电加热器所用原材料应符合下列要求：
1. Raw materials used in electric heaters shall meet the following requirements:
① 绝缘材料氧化镁的成份应符合HG3-1294-80《氧化镁》规定；
The composition of magnesium oxide in insulating material should conform to the requirements of HG3-1294-80 Magnesium oxide.
② 氧化镁须经烘干后使用；
Magnesium oxide must be dried and used.
③ 电加热器所用的电热材料为0Cr27A17Mo2高电阻电热合金丝，其工作温度为400°C，技术要求按GB1234《高电阻电热合金》规定；
(3) The electric heating material used in the electric heater is 0Cr27A17Mo2 high resistance electric heating alloy wire, whose working temperature is 400 C. The technical requirements are stipulated in GB1234 High Resistance Electric Heating Alloy.
④ 电加热器保护套管材料为1Cr18Ni9Ti耐热不锈钢管。其技术要求按YB804《不锈耐酸钢无缝钢管》规定。使用其它材料由制造厂与用户商定；
(4) The protective sleeve material of electric heater is 1Cr18Ni9Ti heat-resistant stainless steel pipe. Its technical requirements are stipulated in YB804 Seamless Stainless and Acid-Resistant Steel Pipe. The use of other materials is agreed between the manufacturer and the user.
⑤ 电加热器用的保护套管内部去除毛刺后，再用汽油或煤油清洗干净，并吹干后才能使用。
_After removing burrs in the protective sleeve used in electric heater, clean it with gasoline or kerosene, and blow dry before use.
2、电加热器成品应符合下列要求：
2. The finished product of the electric heater shall meet the following requirements:
① 电加热器的额定工作电压为220±20V。直流100V，低压50V；
The rated working voltage of the electric heater is 220+20V. DC 100V, low voltage 50V;
② 电加热器插入长度在1m以内的，其中心线直线度不大于?0.3mm；插入长度在1-2m的，其中心线直线度不大于?0.4mm；
(2) The insertion length of the electric heater is less than 1 m, and the straightness of the central line is not more than? 0.3 mm; the straightness of the central line is less than? 0.4 mm when the insertion length is 1-2 m;
③ 插入部分直径偏差为-0.20mm/-0.50mm；
(3) The diameter deviation of insertion part is -0.20 mm/-0.50 mm;
④ 插入部分长度偏差为±5mm，发热长度偏差为±5mm，底部冷端长度为25-30mm；
(4) The length deviation of insertion part is (+5mm), heating length deviation is (+5mm), and the length of bottom cold end is 25-30mm;
⑤ 电加热器在使用时要求发热均匀，不允许有局部过热现象。
The electric heater should be uniformly heated in use, and local overheating is not allowed.