西班（bān）牙研製波浪發電裝置 2009年將放入海中運行

　　為了正確選擇自動控（kòng）製閥的通徑，用（yòng）戶（hù）需要了解下列事項：
　　To properly size an automatic control valve you need to know the following:

• *高和*低的（de）進口（kǒu）壓力（lì）
  Highest and Lowest inlet pressures
• 出口壓力
  Outlet pressure
• *大流量（liàng）要求
  Maximum flow requirements
• *小流量要求
  Minimum flow requirements

　　步驟1：利用高流量表，並且在橫軸上找出符合用戶*大流量要（yào）求的流量值。
　　Step 1: Utilize the high flow chart and select the flow as found on the horizontal axis which corresponds with your maximum flow requirements.
　　步驟2：從這一點劃垂（chuí）線，延（yán）伸到與相應的*小壓差的水平（píng）線（xiàn）相（xiàng）交。（此時，*小壓差將是（shì）*低（dī）進（jìn）口壓力減（jiǎn）去所需要的出口壓力，這（zhè）也就是所說的∆P。）
　　Step 2: From this point draw a vertical line until you intersect with the horizontal line corresponding with the minimum differential pressure. (Your minimum differential pressure will be the lowest inlet pressure minus the desired outlet pressure, this is also known as the delta P.)
　　步驟3：從這一點向（xiàng）右移動直到**個閥門的通徑線。這就是在25英尺/秒間（jiān）歇流量時（shí）應（yīng）該采用的*小（xiǎo）閥門通徑。如果*大（dà）流量是連續的，那麽不要超過*大連續流量表上所列的美製加侖/分鍾（20英尺/秒）。
　　Step 3: From this point move right to the first valve size line. This will be the minimum valve size which should be used on intermittent flow of 25 ft./sec. If maximum flow is continuous, then do not exceed the GPM (20 FT./sec.) listed on the maximum continuous flow table.

　　步驟（zhòu）4：利用（yòng）流量表，在豎軸上找（zhǎo）到*大壓差（chà）。（用戶的*大壓（yā）差將是*高進（jìn）口壓力減去所需（xū）要的出口壓力，這也就是所說（shuō）的∆P。）
　　Step 4: Utilize the flow chart and select the maximum differential pressure as found on the vertical axis. (Your maximum differential pressure will be the highest inlet pressure minus the desired outlet pressure, this is also known as the delta P.)
　　步驟5：從這一點劃水平線與步驟（zhòu）3選擇的閥門通徑相應的線（xiàn）相交。
　　Step 5: From this point draw a horizontal line until you intersect with the line corresponding to the valve size as selected in step 3.
　　步驟（zhòu）6：從（cóng）這一點劃垂線向下與橫軸相交。這就是以這些變量為基礎的（de）閥門的（de）*小流量能力。
　　Step 6: From this point draw a vertical line down to the horizontal axis. This will be the minimum flow capabilities of the valve based on these variables.
　　注意：1) 如果通過步（bù）驟6得到的*小流量（liàng）能（néng）力（lì）比用戶實際的*小流量要求高，則用戶應該考慮采用並聯安（ān）裝方式。采用這個*小流量能力，從步驟1開始選擇用戶需要的用於低流量旁（páng）路的通徑。
　　　　　2) 采（cǎi）用空**表（biǎo）並且確定進口和出口壓力的（de）相（xiàng）交是否落在陰影區域（yù）內（nèi）。如果是，用（yòng）戶應該考（kǎo）慮（lǜ）串聯安（ān）裝（zhuāng）方式。兩個閥門都應該按照上述步驟選擇通徑。
　　Notes: 1) If the minimum flow capability obtained from step 6 is above your actual minimum flow requirements, you should consider a parallel installation. Using the minimum flow capability, begin at step 1 to select the size you will need for this low-flow by-pass.
　　　　　2) Use the cavitation chart and determine if the intersection of the inlet and outlet pressures falls in the shaded area. If so, you should consider a series installation. Both valves should be sized in accordance with the above steps.

壓降指數 - 減壓閥
PRESSURE DROP INDEX - PRESSURE REDUCING VALVES

　　通過從*大進口壓力（lì）減去所（suǒ）需要的出口壓力來計算壓差。找出壓差線（xiàn）上的數字（zì），並且注意出口（kǒu）壓（yā）力指數。這是不會落入空穴（xué）區的*低（dī）的出口壓（yā）力設置。美國瓦茨自動控製閥的（de）結構將可能導致空穴現象（xiàng）的閥門損壞潛（qián）在危險降低到*小程度。避免（miǎn）在空穴區（qū）域內持續運行。
　　Calculate the pressure difference by subtracting the desired outlet pressure from the maximum inlet pressure. Find the number on the pressure difference line and note the outlet pressure index number. This is the lowest outlet pressure setting allowed without failing into the cavitation zone. Design of the WATTS Automatic Control Valve minimizes potential valve damage that can be caused by cavitation. Avoid continued operation within the cavitation zone.

空**表
CAVITATION CHART

　　閥門通徑選擇後（hòu），在（zài）這個圖表中找出（chū）進口和出（chū）口壓力。如果交（jiāo）點落在陰影區域，則可能產生空穴（xué）。應該避免在空穴區域內持續運行閥門。請谘詢美國瓦茨ACV，了解其他解決方案。
　　After selecting valve size, locate inlet and outlet pressures on this chart. If the intersection point falls in the shaded area, cavitation can occur. Operation of valves continually in the cavitation zone should be avoided. Consult Watts ACV for alternatives.