What is the difference between 2-ways valve and 3--ways valve?

Dear Saffii, a3-way valve will by-pass chilled water, while a2-way valve will stop water flow. this means that flow rate will stay the same if you use3-way valves in a circuit, but if you use2-way valves, flow rate will fluctuate as the valves open and close. hence, you have to use a pump with variable speed with2-way valves and constant speed with3-way valves. for info, the variable pump will react to pressure built-up on the reticulation line: as2-way valves close, pressure will build up on the line; the pump will slow down to lower the pressure to normal level. Hope this helps. Regards

2 way valve will modulate flow.2 way valve used in variable pumping system.3 way valve will bypass/divert the flow.3 way valve used in constant pumping system.

-2 way valve:

يستخدم مع الطلمبات ذات السرعه المتغيرة و هو اكثر شيوعا و اكثر توفيرا للطاقه مع ارتفاع سعر الابتدائى للمنظومه

-3 way valve:

يستخدم مع الطلمبات ذات سرعه ثابته و هو اقل فى توفير الطاقه و السعر الابتدائى للمنظومه اقل

الصمام الثنائى المخرج بيستخدم قبل الفان كويل . عند استخدام مواتير مياه متغيره السرعات

الصمام الثلاثى المخرج بيستخدم مع مواتير المياه الثابته السرعه

2 way valve used with variable speed3 way valve used with constant speed

1-3way valve is a control valve for water flow and used before F.C.U,S and A.H.U,S in constant speed pumping systems in chilled water centeral air conditioning systems.

2-2way valve is as per above but used in varaible speed pumping system.

both installed in the return line,2 way for variable pumping flow and variable return temperature,3 way valve is for constant pumping flow and constant return water temperature.

the two way valve have only two positions on/off and used in the case of use of constant speed pumpsThe three way valve who shall convert the path of water from inside the cooling coil to the outside and is used in the case of use of secondary pumps with variable speed

 thanks...but what the location these valves will be installed the supply line or return line of the network????

the2 way vavle used with variable speed pump in the FCU returne pipe with a need of bypass after it. but the3 way valve used with constant speed pumps and the bypass out from the valve.

There is no different of2 ways valve and3 ways this is the maximum outlet and inlet valve or so called butterfly valve depending of the connection lines all  is ditribution valve..