This combination of disc springs and dual valve seal rings protects against expansion and contraction due to heating and cooling. This ensures dependable operation, even after years of service.

盘簧与两个密封环的组合，可防止因加热或冷却产生的膨胀和收缩，由此确保阀门即使使用多年后仍运行可靠。

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Same function as DPP-250: frequency control, adjustable stroke, touch heating, positive forming, capsule orientating, image and character register, air cushion heating-seal and chequered plates.

产品介绍：功能与250型类同：变频调速、行程可调、接触加热、正压成形、胶囊调头、图文对版、气垫热封、上下网纹。

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When Pipes, valves and water seal equipments is freezing, only hot water or steam heating can be use to thaw, and open fire is prohibited.

管道、阀门和水封装置冻结时，只能用热水或蒸汽加热解冻，严禁使用明火烘烤。

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David Dwyer, the contractor who built the Yerke family's home and installed their geothermal system, says that if you have an old and drafty house you should, before putting in a fancy heating system, put in new windows, seal leaks and add insulation.

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