backn.后面；背脊；靠背；后背；后卫vt.支持；后退adv.向后地adj.向后的；后面的；偏远的；过时的；积欠的back bias反偏压,反馈偏压,回授偏压,背面照明

1. We strongly recommend installing a safety relief valve in addition to the unloader to add more protection from dead-heading.
   我们强烈建议，除了减压器外，再安装安全卸压阀来防止跑空。
2. Follow manufacturers instruction regarding the installation and adjustment of any unloader and safety relief valve you choose.
   按照操作守则关于你所选择的减压器和安全卸压阀的安装和调节指示。