back valve

基本解释

Casing back pressure valve plays a important role in well cementing operation as a casing accessories.
套管回压阀作为一种简便的套管附件，在固井施工作业中起着重要作用。
According to flow in a different, balanced spool valve the pressure can be pre-pressure, can also be a back pressure valve .
根据流向不同，平衡阀芯所受的压力可以是阀前压力，也可以是阀后压力。
The performance and structure of existing back valve are introduced, and an ultra-low pressure startup back valve, which can be fixed freely in any pipes with any directions, is designed.
对现有止回阀的性能、结构进行了分析，设计了一种可以随意安装于各种方向的管道中的超低压力启动上回阀。

We've yet to hear back from Valve for clarification.
ENGADGET: Valve's Gabe Newell confirms work on new game engine, still won't answer your Half-Life 3 queries
Even if the Steambox initiative fizzles, there's always the massive ongoing success of Steam's digital storefront to fall back on. 2013 may be the year that Valve attacks, but it's not just the company's internal hardware projects that are up for the challenge.
ENGADGET: 2013: The year that Valve attacks HD
The goal is to tighten up or otherwise improve the faulty valve, called the esophageal sphincter, that lets acid reflux back into the esophagus.
FORBES: Health