Chemical Injection

[mead]

Hello All,

I am working on the design of a chemical injection system and have a few questions (the system is for injecting iodine into a water stream).

Would it be better to have the injection point in the side or the top of the water pipe? If it is in the top of a straight run of water pipe would a check valve be needed to prevent back flow into the chemical line? Also, if it is in the top of the water pipe would there be any venturi effect causing slight negative pressures?

Any and all opinions are appreciated

Thanks

 

[mucour]

The only help I can render from oil and gas application is that a check valve should be installed on the injection line before entrance to the main line

 

[hero123]

i am in a petroleum industry and i design all my inhibitor injection system in the horizontal plane, that is, injection from the side in the same horizontal plane. depending upon the volume and pressure of injection, the injection piping size can be worked out. if injection piping is within 1/6th of main pipe, i use a Tee for injection. if the ratio is even poorer i use weld-o-lets. The tees or weld-o-lets are fitted in the horizontal plane thereby ensuring side injection.
A check valve is a must in the injection system so as to prevent the back flow of the injected fluid in the main pipe in case the pressure in the main pipe is very high as compared to the pressure of the injected fluid. it is further necessiated in case an injector pump is utilised for injection so as to prevent back flow of fluid or any back pressure to the pumping unit.
the venturi effect that u r talking will definitely be there, however it's effects can be ignored in the design.