Hello,
i have confusion in filling my datasheets regarding usage of diaphragm seal, syphon, snubber for a pressure gauge

As far as i know diaphragm Seal keep process fluid from freezing, gelling. They are filled with non compressible liquids which transmit the process pressure to the protected pressure element.

Snubber are used to suppress the effect of pressure pulses and pressure peaks in harsh applications such as on reciprocating pumps and compressors

Syphon filled with water should be installed between the gauge and the process line.It acts as a cooling coil and protects the gauge from high temperature vapors.

And now my confusion is regarding usage of diaphragm seal along with syphon?
or
Diaphragm seal along with snubber?

When a diaphragm seal is used for a pressure gauge can i use syphon or snubber along with diaphragm seal?

i got this doubt because i have a application in which diaphragm seal is used in discharge of pumps (shown in P&ID) and i have to use snubber for reducing pulsation.

and for steam application too diaphragm seal is shown in P&ID so syphon can be used along with diaphragm seal?

and one more doubt for me is position of syphon! Can it be placed above instrument manifold or below?

To add my project is a Sulphuric acid plant

please respond me soon and help me as i have to deliver my datasheets As soon as possible.

Thanks in Advance,
With Regards,
Gopi.

 

> i have confusion in filling my datasheets regarding usage of diaphragm seal, syphon, snubber for a pressure gauge. As far as i know diaphragm Seal keep process fluid from freezing, gelling. <

The use of Diaphragm seals is primarily but not limited to preventing corrosive liquids or solids from entering the gauge or Instrument as the measuring elements cannot always be made of compatible material

> Snubber are used to suppress the effect of pressure pulses and pressure peaks in harsh applications such as on reciprocating pumps and compressors <

Correct

> Syphon filled with water should be installed between the gauge and the process line.It acts as a cooling coil and protects the gauge from high temperature vapors. <

It acts in a similar fashion as the diaphragm by preventing the process vapours from entering the element AND Note they are not always filled with water, you would normally condense the vapours you are trying to measure

> When a diaphragm seal is used for a pressure gauge can i use syphon or snubber along with diaphragm seal? <

You do not need to use a siphon as the diaphragm is doing the same task and could possibly act as an snubber also but this depends on the Pulses

> i got this doubt because i have a application in which diaphragm seal is used in discharge of pumps (shown in P&ID) and i have to use snubber for reducing pulsation... and for steam application too diaphragm seal is shown in P&ID so syphon can be used along with diaphragm seal? <

I would not recommend a diaphragm seal for Steam applications a conventional Bourdon Tube Pressure Gauge with a siphon is all that required

> and one more doubt for me is position of syphon! Can it be placed above instrument manifold or below? <

If it is Steam service the Siphon should be located between the process valve and the gauge manifold

> To add my project is a Sulphuric acid plant <

What are you trying to measure?

 

> What are you trying to measure? <

i am trying to measure pressure for a sulphuric acid plant for which pressure gauges are place at dischrage line of motors in dearators etc

I need little more clarification regarding position of syphon...

"Can this be placed above instrument manifold or below (between instrument manifold and piping isolation valve?)?"

this i need because in my hook ups it placed below instrument manifold which i want to point to my manager this as a mistake but i am not confident. when i did a little research on other project hook ups i found mostly it is placed above instrument manifold. and my designers saying it can be placed even below instrument manifold as per there experience.i am really confused regarding this. Please respond me as soon as possible.

with regards,
Gopi

 

If your pressure gauge is installed below the tapping point you don't really need a siphon because the vapor will condense in the tubing thus protecting the gauge.

Perhaps an example would help..

If you mount a pressure gauge on top of a steam line the steam will enter the gauge and condense running back into the line, very quickly the gauge will reach steam temperature.

The siphon provides a liquid trap between the live steam and the gauge. If you mount the gauge below the line the steam will condense in the tubing but be unable to run uphill back in to the line.
So in short, you use a siphon for hot condensing vapors where the gauge is above.

Hope this helps.
Roy

 

if you want to measure steam, you can have one syphon , this is for decreasign the temperature , to avide harm the pressure gauge, see below picutre, syphon is as below picture shows:https://www.silverinstruments.com/product/pressure-measurement/pressure-gauge/