positive valve

The positive crankcase ventilation valve and gas caps with air-pollution control valves reduce volatile organic compound loss.

曲柄轴箱通风阀和配有废气帽的空气污染控制阀（使用）减少挥发性有机混合物释放有积极作用。

Its design features include a double check valve assembly to assure positive, dependable seating protection.

这种结构特点在于包括一个双止回阀总成,确保积极 、 可靠的密封保护.

As for the control of the negative surge wave, quick opening regulating valves can be used, while the positive surge wave, low pressure relief valves can be used in pressure relieving besides sensitive regulating valve system, in order to reduce surge pressure.

对于故障性负水击波，可采用快速调节阀控制，而对于正水击波，除采用反应灵敏的调节系统外，还可采用低压泄压阀泄压，以降低水击幅度。

Conclusions The clinical features of drug addicts with IE are: fever, inertia, panting, coughing, cardiac souffle, positive of blood germiculture and pulmonary infection. Echocardiogram is important to diagnosing the infection of tricuspid valve.

结论静脉药瘾并发IE者临床特征为发热、咳嗽、气促，心脏杂音，血细菌培养阳性合并肺感染，超声心动图检查对右心感染有重要价值。