Valves Symbols used in P&ID and Piping Isometric drawings – With Detail Explanation


Welcome to the hardhatengineer.com. I am Varun Patel. In this video, you will learn about valves
P&ID and ISO drawing symbols. Please subscribe to my channel because it
helps me to increase my reach on YouTube and you will also get regular updates on a new
video. You can subscribe right now by just clicking
the subscribe button on the right-hand side of the screen. Let’s start with some generic P&ID symbols
of the valve. Here in this slide you can see commonly used
symbols for valves. These symbols are generic in nature. For example, first symbol of valve. Now when you see the symbol on drawing, it
just gives you indication that some kind of valve is used, but it will not give you information
about the type of valve. Whether it is a gate, globe or plug. There are dedicated symbols for gate, globe,
plug, ball valves which I will explain you in minutes. Simlierly next two symbols which are three
way and four way valve. It can be plug or ball valve. Next two symbols are of check valve and stop
check valve. These check valves can be swing check or lift
check valve. The next symbol is of excess flow valve. You can see that it is same as check valve
with only difference is the written text, below the valve symbol. You have to be very carefull while reading
this type of symbol as it can easily overlook. The last symbol is of automatic recirculation
valve. This type of valve is used in pump discharge
line to ensure the pump will not suffer from low inlet pressure which leads to cavitation. On this slide, the first symbol is of angle
valve. In most cases, globe valve is used as an angle
valve. Next symbol is of relief valve that used to
protect the piping system or equipment from overpressure. Now the breather valve is used on the cone
roof tank. This valve serves the function of the relief
valve and vacuum valve. In the event of over-pressure this valve release
the pressure and in case vacuum are created in the tank, this valve allow air to enter
the tank. Just like breathing air in and out. Vacuum valve prevents damage to the equipment
from negative pressure. Pilot operated relief valve are just working
like relief valve, but are used for large size piping. In this type, a small relief valve is used
to operate the main relief valve. This arrangement is cost effective in large
size relief operation. Now I will explain you the specific valve
symbol that used in P&ID and isometric drawings. You can learn all these types of valve in
detail along with more than 18 types of valves, purchase my course, how to be an expert in
piping valves. Link is given in the description. On this slide, you can see the gate valve. Now see the P&ID symbol for gate valve. It is modification of generic valve symbol
by inserting vertical line between two triangles. Three symbols shown below are the gate valve
symbols used in isometric drawings. The first is for butt-welding ends, second
is for flanged end valve and the third one is for socket end connection. For globe valve, symbol is modified by adding
a small dark circle. You can see that P&ID and isometric symbols
are almost same with only change in end types. Next is ball valve. You can see that there are two P&ID symbols
for ball valve. The reason is that P&ID and isometric drawing
symbols are changed from company to company. So if you switch the company, you should be
aware of this. Similarly, you can see the ISO symbols for
butt, flanged and socket ends ball valve. Same as ball valve, needle valve also has
a multiple P&ID symbol. If you can see that even these symbols are
different but still you can easily interpret. If you are using second P&ID symbols, your
isometric symbol will be changed accordingly. For plug valve, the first symbol is a bit
confusing with globe valve. If you remember the symbol of globe valve,
it has a dark circle in between the triangle, whereas here only circle outline is there. So when you see this type of symbol, better
to double check the drawing. Butterfly valve symbol is the only symbol
where full triangle is not used. If you refer first symbol, it is similar to
a globe valve but triangle is not full. Alternative symbol is clearer in this case. For isometric symbols, you can see that there
is no socket end butterfly valve. Here is the diaphragm valve. There is no butt-welded diaphragm valve available. Most diaphragm valves are flange type and
they are used to handle process media with solid particles. On this slide, you can see the symbols with
a special notes. The first symbol is of special valve. The word NC return below the second symbol
is more important. It indicates that this valve remains closed
during normal operation. Now the next two symbols are also used alternatively
to show the valve position during normal operation. The last symbol used to show pressure end
of the valve. The shaded are showing the pressure side of
the valve. If you want to learn about more than 18 types
of valve in detail, you can buy my course, how to be an expert in piping valves. Link is given in the description. This is all about P&ID and isometric symbols
of Valves. Don’t forget to subscribe to my channel. Please like and share my video with your friends. If you want to request a video, write in the
comment. See you soon goodbye take care.

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13 thoughts on “Valves Symbols used in P&ID and Piping Isometric drawings – With Detail Explanation

  1. Your content is godfather for chemical
    engineer also for fitter and mechanical
    JORDARRR!!!! Bapu
    ๐Ÿ‘๐Ÿ‘๐Ÿ‘๐Ÿ‘๐Ÿ‘

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