**@&@** SUPPLY RETURN SYSTEMS

FLYFISHER

I AM WORKING ON AN OLDER HOT WATER SYSTEM. HEAT SOURCE IS A STEAM TO WATER EXCHANGER. THE PIPING IS SUPPLY RETURN 1 1/2" SUPPLY REDUCING TO 1/2" AT THE LAST OF 15 CAST IRON RADIATORS. RETURN STARTS OUT AT 1/2" AND INCREASES AS IT PICKS UP RADIATORS ON WAY BACK TO CIRCULATOR. (NOT THE BEST TO START WITH). THE CUSTOMER WANTS TO INSTALL A NEW BURNHAM ALPINE 210 BOILER THE HEAT LOSS IS 187,000 (SO FAR SO GOOD NOT A BIG PROBLEM) THE CUSTOMER ALSO WANTS TO INSTALL NON-ELECTRIC ZONE VALVES AT EACH RADIATOR SO I WILL NEED TO INSTALL A BY-PASS TO KEEP THE PUMP FROM DEAD HEADING. HOW DO I SIZE THE PUMP AND BY-PASS SO THAT I DON'T RUN HEADLONG INTO A PROBLEM THIS WINTER? DOES ANYONE MAKE A BYPASS RELIEF VALVE OTHER PARAMETERS:

60' 1 1/2" SUPPLY

30' 1 1/4" SUPPLY

40' 1" SUPPLY

60' 3/4" SUPPLY

20' 1/2" SUPPLY

RETURN IS RUN IN OPPOSITE DIRECTION WITH THE SAME LENGTHS OF PIPE  STARTING WITH 1/2" AT THE FIRST RADIATOR TO 1 1/2" AT CIRCULATOR

I CALCULATED THE FLOW REQUIREMENT AT 18.8GPM

THE HEAD LOSS THROUGH THE BOILER AT 20 DEGREE DELTA T IS 14.4FT

HOW DO I CALCULATE THE LOSS THROUGH THE PIPING SYSTEM?

Unknown

It sounds like,,,,

how  we all used to balance the radiation, not a bad thing(at the time), but the technology is much better now. TRV`s are a GREAT choice for control,, Have you ever considered one of   these?   ,,,, no bypass is necessary and the existing piping scheme should work well.Sorry,,,, after 4 tries I can`t get the link to post,,, I was talking of the Wilo ECM. Don`t understand what I`m, doing wrong!!!