Water Pump Pressure

slabman · 03-20-2008, 08:45 PM

I need to install a larger capacity pump to handle an R.O. water filtration system. My present pump is rated a max 35 psi, while the R.O. system needs a minimum of 40. Considering the R.V. mfrs. seem to caution against going over 40 psi in their systems, I'm wondering how high I can go, realistically, and not blow my plumbing lines, which are of PEX tubing in this coach. The new pumps I'm considering are the Shurflow 4.0 rated at 50 psi and the Shurflow 5.7, rated at 65 psi. The 5.7 would, of course, be preferable to make more product water faster than the smaller pump, but do I dare go there?

slabman · 03-20-2008, 08:45 PM

I need to install a larger capacity pump to handle an R.O. water filtration system. My present pump is rated a max 35 psi, while the R.O. system needs a minimum of 40. Considering the R.V. mfrs. seem to caution against going over 40 psi in their systems, I'm wondering how high I can go, realistically, and not blow my plumbing lines, which are of PEX tubing in this coach. The new pumps I'm considering are the Shurflow 4.0 rated at 50 psi and the Shurflow 5.7, rated at 65 psi. The 5.7 would, of course, be preferable to make more product water faster than the smaller pump, but do I dare go there?

Rocky Larson · 03-21-2008, 11:53 AM

I have used a ShurFlo 5.7 for 4 years and have had no plumbing/pressure problems. I also just recently went to the higher pressure (55+lbs) regulator available from Camping World to improve shore water pressure. However, most of the time I prefer the pumps improved pressure and only use the shore water to fill the tanks.
Good Luck,

Jackm · 03-25-2008, 01:24 AM

Most RV water systems are tested at 100 psi by the manufacturer. While its not suggested that you maintain this level, it does indicate that you'll be fine with any of the popular RV pumps (i.e. the Shurflow 5.7). Since RO systems require higher pressures, make sure that your water regulator isn't too restrictive (i.e. under 40 psi). There's a regulator made by Watts that can be adjusted to any level you want. It would be ideal for your system. I've seen them at Camping World for less than fifty dollars. Best of luck.

Jack

speed racer · 03-25-2008, 04:42 AM

Keep in mind that the main problem is restiction in the system. My 05 dolphin had a built in pres.reg. @ 50# but when I took it apart it only had a hole about 3/16" in diameter. I replaced it with one that was just a check valve to keep the WP pres. from coming back out and got a watts whole house pres. reg from Lowes set it at 50# and now have all the water I need.