Reply
 
Thread Tools Search this Thread Display Modes
 
Old 07-30-2019, 12:59 PM   #1
Newbie
 
City: Wilmington
Country: USA
Join Date: Jun 2013
Posts: 3
What is a typical for raw water system pressure?

Does anyone know what typical raw water system pressure to expect at idle and max cruising RPM?

The repair was prompted because a coolant pipe was popping out of the heat exchanger and leaking. It is sealed with o-rings but it is not held securely enough (in my opinion) to suggest that it is intended to resist more than a few PSI of water pressure. I measured an alarming 10 PSI at idle and a little more than 40 PSI at 2000 RPM. After soaking the internals of the raw water system with vinegar (overnight) and removing a few zinc bits the pressure at went from nearly 40 PSI at 2000 RPM to less than 20 PSI. The pressure at idle on both motors is now less than 7 PSI.

The leaking problem appears fixed but since the system appears to be designed for low pressure, I am wondering what is normal.

Motors are twin 135 hp Volvo TAMD40B.
__________________
Advertisement

thesnide1 is offline   Reply With Quote
Old 07-30-2019, 02:46 PM   #2
Guru
 
City: Seaford Va on Poquoson River, VA
Country: United States
Vessel Name: Old Glory
Vessel Model: 1970 Egg Harbor 37 extended salon model
Join Date: Jan 2016
Posts: 2,180
If engines are running at normally operating temp, and you have a decent flow out the exhaust, and its not leaking, then its good.
Your pressures sound realistic.
Pressure could rise if the heat exchanger is clogged. And you cleaned it.
The raw water pump is going to pump whatever it can in gallons per hour at a given rpm, these are not specified for pressure, more like flow. the raw water system will have little backpressure, water is just flowing in, through, then out.
sdowney717 is offline   Reply With Quote
Reply

Tags
heat exchanger, raw water pressure, tamd40b

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 03:44 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012