| 3. | The standard of the products include national standard , petrochemical machinery industrial standard , america standard , japanese standard , germany standard , non - standard flange , which are used in joint valve , pump , petroleum , chemical machinery , pipeline fittings , and equipment components and son on 产品有国标、石油化工机械行业标准、美标、日标、德标、非标法兰等,广泛适用于连接型式的阀门、泵、石油、化工机械、管路附件和设备零部件等行业。 |