| 1. | Four required per backflow preventer 每个防回流阀需要四个。 |
| 2. | For use with backflow preventer test cocks to protect from damage 用于防回流阀测试旋塞,防止受到破坏。 |
| 3. | The system should be flushed before the backflow valve is installed 在安装回流阀之前系统应该进行冲刷。 |
| 4. | Installing a backflow preventer in a pit or vault is not recommended 不建议在坑内或拱顶内安装防回流阀。 |
| 5. | Especially made for testing all reduced pressure zone backflow preventers 专用于检测所有减压区防回流阀。 |
| 6. | A check valve may be required ahead of the backflow preventer 此时在防回流阀前面可能需要安装一个止回阀。 |
| 7. | Also , mechanical backflow preventers and air gaps can be bypassed 此外,机械式防回流阀和气隙可以作为旁路。 |
| 8. | Certified testers of backflow assemblies must conduct this test 这种测试必须由有资格证书的防回流阀总成检验员进行。 |
| 9. | Certified testers of backflow assemblies must conduct this confirming test 必须由有资格证书的防回流阀检测人员进行这种确认检测。 |
| 10. | Backflow preventer manufactured from 300 series stainless steel for corrosion resistance 防回流阀采用耐腐蚀的300系列不锈钢制造。 |