闸阀
GATE VALVES
如今行业内，闸阀最常用作关闭阀，用于要求压降最小，能够双向启闭的应用场合。闸阀不适用于节流应用场合。长期处于未全开状态通常会损坏阀座表面。闸阀可配置多种楔形闸板结构(实心、弹性和对开式)，以最好地满足特定应用环境的要求(请参阅第6页)。闸阀通常采用手轮操作，但是也可以配置齿轮操作机构，电动马达执行机构。或缸体(气动或液动)执行机构，以实现远程操作。参阅执行机构和附件章节，了解更多细节。
Gate valves are the most commonly used shutoff
valve in the industry today. They are used where minimum pressure drop
and bi-directional on-off service is required. Gate valves are not designed
for throttling service. Prolonged use in the partially open position will
generally damage seating surfaces. Gate valves are available with a number
of wedge configurations (solid, flexible and split) to best meet the specific
service conditions (see page 6). Gate valves normally
are handwheel operated, but are also available with gearing, electric
motor actuators, or cylinder (pneumatic or hydraulic) actuators for remote
operation. See Actuators and Accessories section for more detail.
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截止阀
GLOBE VALVES
截止阀用于需要节流，或既需要节流也需要关闭的应用场合。截止阀也可以用作启闭阀门，但是由于截止阀的压降较高，因此通常局限于在阀门正常情况下处于关闭状态，并且当阀门开启时，压降并不是重要的影响因素的应用场合下使用。正常情况下，安装的截止阀要使得流体从阀瓣下端流进，但是，某些应用场合，流体从阀瓣上方流进可能更加有利。标准的截止阀，虽然结构上适用于节流和关闭，但是不能在小于10%的开启度下长期节流使用。否则阀内件可能会受到损坏。采用通径更小的截止阀，或者采用V形端口阀内件截止阀，增加开启度，往往就可以解决这个问题。V形端口阀内件截止阀比塞形阀瓣或球形阀瓣截止阀具有更加线性的节流曲线，但是，所有这些类型的截止阀都不建议连续用于严格的节流应用中，这种情况可能需要采用控制阀。美国太平洋阀门公司为用户的应用提供建议。截止阀可以配置全系列的手动或者远程执行机构。参阅执行机构和附件章节，了解更多细节。
Globe valves are used where throttling or both
throttling and shutoff are required. They can also be used for on-off
service, but because of high pressure drop, this is generally confined
to applications where the valve is normally closed and pressure drop is
not important when the valve is open. Normally globe valves are installed
with flow under the disc, but under certain conditions flow over the disc
may have advantages. Standard globe valves, because they are designed
for both throttling and shutoff, should not be used for prolonged throttling
at less than 10% open. Internal damage can occur. Using a smaller valve
or V-port trim to increase the percent open will often solve this problem.
V-port trim has a more linear throttling curve than plug or ball discs,
but none of these trims are recommended for continuous severe throttling
which may require using a control valve. Pacific Valves will be glad to
advise you on your application. Globe valves are available with a complete
range of manual or remote actuators. See Actuators and Accessories section
for more detail.
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