Hello all,

If there is application to reduce pressure from 140 psi bar 85 psi, can we use pressure reducing valve (diaphragm type) OR plunger type control valve.

On the otherhand please find my clarifications as below:
1. what are the main feature for each valve type in this application?
2. What is the application to use plunger type control valve?


The attached file for PRV brand cla-val, I will attach in my reply the other type plunger control valve brand ERHARD model RKV.

Thanks in advance our experts.

Best Regds,
Baram

The attached file for ERHARD model RKV

• http://files.engineering.com/getfile.aspx?folder=2f13c0ca-c782-4b91-98f4-4f

The application is water transmitting pipelines,

Regds,
Baram   

Size - Cost could be a parameter for selection. For sizes above 26-32 inch I believe claval, singer type valves are not applicaple.  

Hello Valving,

Size is 20" (500mm)

it would be better to receive prices for both sizes.
rkv valve are more like axial valve so Cv values could be higher, but now sure.
beside claval like valves are man-free as they are pilot operated whereas rkv will be electric actuated.
if you look far rkv manufacturers erhard, vag, etc from germany and there are some italian I guess.  

Hi Valving,

Many thanks for your advice.
For plunger valves as RKV they only type for this types that control pressure or flow rate(nothing mention about reducing pressure/sustaining/relief/ level control/...etc) so I see claval pilot operated valves that having wide range of applications and they mention it clear for each model.
For example: claval have pressure reducing valve, also they have another model pressure relief valve, also different one is pressure sustaining valve, beside flow control valve, ...etc so claval depend on one basic main valve body and change the pilot type and looping so the function of whole valve will be changed as per above mentioned functions.
I did not see these functions in RKV? not mentioned!!!
As I know that for model claval pressure reducing valve that the valve will reduce the downstream pressure and maintain it as per pilot set point without any big change in the flow rate.
did RKV model will keep the same mechanism if we use it as pressure reducing valve.
To be honest with you I have less experiences on plunger type as RKV, I don't understand how this valve work to reduce pressure.

Baram
 

baram you are right, claval valves use same body mainly with some different arrangements and pilots they could perform different operations.

Personally I only dealt with RKV control duty but uploaded a file indicating some details altough this brand is no longer available, I guess.

you may also check mokveld website, they produce similar valves but far complicated for your application I guess.

I believe claval type valves will be better for your application.
There are others like ross, ga, singer, dorot, etc.
what is the project destination?

• http://files.engineering.com/getfile.aspx?folder=b8d2d287-9035-48a7-ac92-5e

Good Day Valving,

Thanks, as you said that you dealt with plunger type rkv valves, so in brief could you advise the functions this valve will do and How?

I need you help from you awarness of this types of plunger valves.

I read catalogs for RKV ERHARD, VAG, Magwen, Nincini,Mockvield and all mentioned for plunger valves that control pressure and flow they type it as general!!!
As I know from my little experience in this field that to use control valve you should specify the funcion/functions you need as reducing pressure/ relief / sustain/pump control/ level control/ flow control, but for this type RKV they did not mention any thing about the functions, only mentioned control pressure/flow!!!!!

For your attached Magwen( they still live in Germany)also the same  general features and functions , not specified well.


The project for water transmission application in KL, Malaysia.

Thanks in advance for your assistance.

Baram
 

Baram,
Below video could help in understanding the RKV I hope

http://www.youtube.com/watch?feature=player_embedded&v=OUoICRdKNoM#!

altough the instruction is in German

Thank you very much valving as I see it is flow control valve parallel with pressure control , this valve always will be in dynamic movements always so can not adjust it to mean pressure but for pilot operated pressure reducing valve we can pre-adjust the required pressure so the valve will keep fixed downstream pressure in outlet even fluctuating the upstream pressure the claval PRV valve will remain the adjusted downstream pressure.

Once again Many thanks.
Baram

very good explanation ))

KANE KOGYO in Japan also manufacturers pressure reducing valves.
Kane
Confirm that 500mm is the proper size for you. Just because that is the pipe size, it doesn't mean the valve should be 500mm. Check what your required flow rates are. Perhaps consider a parallel installation (2 much smaller valves). Watts also makes PRVs.
Watts

Suggest you look at ClaVal, FMC Smith, Singer or Dorot type valves.

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http://waterhammer.hopout.com.au/

Pressure reducing valve info: http://pressurereducingvalve.net