美国阀门仪表制造公司,制造了一种新型压力表(Duragage),其特点是安全可靠。这是由于在表的内部安装了起安全作用的泄压膜片,因而,可以防止用苯酚树脂作成的表壳破裂。如图所示,泄压膜片装于表壳的内螺纹中,其周边有O型密封环,同样表的正面也有O型密封环,均用螺纹压环压紧固定在表壳上。 Valve Manufacturing, a US company, created a new type of pressure gauge (Duragage) that is characterized by its safety and reliability. This is due to the installation of a pressure relief diaphragm that acts as a safety element inside the watch, thereby preventing the watch case made of phenol resin from being broken. As shown in the figure, the pressure relief diaphragm is mounted on the internal thread of the case with an O-ring at the periphery and an O-ring at the front of the same gauge, both of which are press-fitted onto the case with a threaded pressure ring.