噴灌系統快速入門 A Quick Primer on Sprinkler Systems (中英文對照)

寫在前面的話

閱讀這一頁對你的幫助將超出你目前的想象。除非你知道如何設計噴灌系統（那你為什麼要讀這篇文章？），或者接受過水力學方面的培訓，否則如果你只懂一點灌溉系統設計背後的基本原理，就會省去很多問題。我會盡量讓你所閱讀的內容對你的腦袋輕鬆些。

噴灌需要能源

噴灌需要兩件事來操作——水流和水壓。當噴灌系統設計失敗時，幾乎總是由於噴頭處水壓不足。這一點很重要，因為如果你像99%使用本教程的人一樣，你只考慮水流。”我的噴灌系統需要（或有）多少水？“這是一個很重要的問題，但它必須與它的姐妹問題“我在噴頭上有多大壓力”齊頭並進。這個問題的“在噴頭上”部分至關重要！請允許我用一個簡單的（如果不是有些愚蠢的話）例子來說明：

去買一個噴頭，任何噴頭都可以，你把它放在水管的末端。現在拿一大桶水來，5加侖是理想的大小水量。現在將噴頭放在地面上（強烈建議放在室外），然後將水倒入噴頭入口。灑水器是否正常工作？它給一個大面積的區域澆水了嗎？不。為什麼不呢？它有很多水啊…。但它沒有任何水壓！你倒進去的水沒有足夠的壓力使噴頭工作。

水壓是使噴頭工作的能量。沒有水壓，就沒有水流（是的，博士女士。在水力學上面說，這不是一個完美的類比——但它對大多數人都適用。）

我們知道水透過管道需要壓力。這也很合理，就像汽車行駛時耗竭汽油一樣，水在流動時也會耗竭壓力！因此，從水開始流過通水系統的管道的那一刻起，它就在消耗壓力。我們在設計時稱之為“壓力損失”。當水透過水錶時，會失去一些壓力。當它透過你院子和房子裡的各種管道時，會失去更多的壓力。擠進閥門和/或防迴流閥會消耗更多的壓力。當水從水源流動到灑水器時遇到的所有東西都會消耗少量水壓。

因此，這裡是一個好的噴灌系統設計的關鍵：在水透過所有這些管道和閥門到達噴頭後，仍然必須有足夠的壓力使噴頭正常工作。如果沒有，它就像上面例子中的噴頭一樣。沒有壓力，世界上所有的水都不能讓它工作！透過使用正確尺寸的管道、閥門等，你可以控制灌溉系統中的壓力損失，朋友們，這就是噴灌系統設計的全部內容！

簡單地說，這裡是噴灌的設計：噴灌的設計就是簡單地控制水進入你的院子和灑水噴頭之間的水壓損失。沒錯，你就要學會如何操縱了（了不得吧，你一直都有一個秘密的願望，希望能夠操縱，對吧？）。

Tip 教程每頁的底部都有一個指向詞彙表的連結。如果你遇到一個你不知道的術語，點選詞彙表就能查詢它。警告：詞彙表中有很多我個人不好的雙關語和奇怪的幽默。

Please Read This！

Reading this page is going to help you more than you can imagine at this point。 Unless you know how to design a sprinkler system （why are you reading this？） or have training in hydraulics， it will save a lot of questions if you understand just a little of the basic principles behind irrigation system design。 I’ll try to keep it light and easy on the brain cells。

Sprinklers Need Energy

A sprinkler requires two things to operate- water flow and water pressure。 When a sprinkler system design fails， it is almost always due to a lack of water pressure at the sprinklers。 This is important because， if you are like 99% of the people using this tutorial， you are thinking solely in terms of water flow。 “How much water do I need （or have available） for my sprinkler system？” That’s an important question to ask， but it must go hand in hand with its sister question， “How much pressure will I have at the sprinkler？” The “at the sprinkler” part of that question is critical！ Allow me to demonstrate by means of a simple， if not somewhat stupid， example：

Go get a sprinkler， any sprinkler will do fine， even one you put on the end of a hose。 Now get a big bucket of water。 5 gallons is an ideal size。 Now place the sprinkler on the ground （somewhere outside is strongly recommended） and pour the water into the sprinkler inlet。 Did the sprinkler operate correctly？ Did it water a good size area？ NO？ Why not？ It had plenty of water。 Ahh… but it didn’t have any

water pressure！

The water you poured into it didn’t have enough pressure to make the sprinkler operate。

Water pressure is the ENERGY that makes the sprinkler do its thing。 Water pressure is like the gasoline for the car。 Flow is like the distance the car travels。 No gas， no travel。 No water pressure， no water flow。 （Yes， Ms。 Ph。D。 in hydraulics， that’s not a perfect analogy- but it works for most people。）

We understand that water requires pressure to push it through the pipes。 It also stands to reason that just as a car uses up gas when it travels， the water also uses up the pressure as it flows！ So from the moment the water starts flowing through the pipes of your water system， it is using up the pressure。 We refer to that as “losing pressure” when designing。 Some pressure is lost when the water goes through a water meter。 It loses some more pressure as it moves through the various pipes in your yard and house。 Squeezing through valves and/or a backflow preventer eats up more pressure。 Everything the water encounters as it moves from the water source to the sprinkler uses up a small amount of the water pressure。

So here is the key to a good sprinkler system design： After the water gets through all those pipes and valves and reaches the sprinkler head， there still must be enough pressure left to make the sprinkler head operate correctly。 If there isn’t， it’s just like the sprinkler you poured water onto in the example above。 All the water in the world won’t make it work without pressure！ By using the correct sizes of pipes， valves， etc。 you can control how much pressure is lost in the irrigation system， and that， my friends， is what sprinkler system design is all about！

So here’s sprinkler design in a nutshell： Sprinkler design is simply manipulating how much water pressure is lost between the point the water enters your yard and the sprinkler head。 That’s right， you are about to learn how to manipulate！ （Come on， you’ve always had a secret desire to be able to manipulate， right？）

Tip

At the bottom of each page of the tutorials is a link to a glossary。 If you run into a term you don’t know， click on glossary and look it up。 Warning： The glossary has a lot of my bad puns and weird humor in it。