Tag Archives: Adding an accumulator tank

Sometimes A Small Thing Can Make A Big Difference

A year ago this week, I posted Happy Wife, Happy Life, which told the tale of how much better things were onboard the good ship Eagle Too after upgrading our freshwater pump to one with a higher flow. As things turned out, the situation wasn’t quite ideal. It needed just a little…more.

Now some diehard salts will tell you that there’s no need for a pressurized water system on a cruising boat—that it’s wasteful of both power and water, and prone to leaving you stuck without a water source (even if your potable water tank is full) in the event of a pump or electrical system failure. I say to hell with that. Maybe if we were young 20-somethings who wanted to take the aquatic equivalent of a cross-country tour in a pop-up VW camper, we might buy into that view. But that’s not who we are anymore. At this stage in our lives we’re more the nautical version of the set-the-cruise-control-on-the-diesel-pusher-RV crowd. With a spare water pump onboard and carrying seven batteries, I’m pretty confident if something breaks we’ll be able to rig up some kind of work around before succumbing to dehydration. Being able to take a decent shower is just too important to the crew’s morale, and then we have things to consider like all the dive gear we’re carrying, which requires a thorough freshwater rinse after each use. So we see a pressurized water system as a need, not a want.

But our poor ShurFlo Aquaking 4.0 GPM pump was taking a lot of abuse. Oh, it could really strut its stuff when we’d fully open a tap to fill a sink or take a nice long shower. But 90% of the time we’re just washing our hands, or rinsing dishes, or brushing our teeth, or some such thing. Something that doesn’t require using more than a moderate trickle of water. Since the pump was the only source of pressure, it would have to rapidly cycle on and off to keep the trickle flowing. Sort of a brrpt-brrpt-brrpt-brrpt thing that was hard on the pump’s pressure switch and internal bypass valve. After a year of that, the brrpt-brrpt-brrpt-brrpt would sometimes continue even after we’d shut the tap. To stop it, we’d have to open a faucet wide for a few moments and then quickly shut it, which was obviously very wasteful.

I was pretty sure our answer was an accumulator tank. Shurflo makes one specifically for use with their small water pumps. It’s a small sealed tank with an internal diaphragm that contains a bubble of pressurized air. When installed in your water system (somewhere on the discharge side of the pump) it evens out the pressure oscillations and lets the pump start and run without cycling. No more brrpt-brrpt-brrpt-brrpt. Which makes for a much happier pump, which should positively affect its will to live. Installation was straightforward, the hardest part was finding 18 inches of reinforced ½” water line, which is apparently in big demand and short supply. West Marine didn’t have any, Home Depot didn’t have any, and Lowe’s only had two feet left from their 100 foot spool. Driving around looking for a bit of hose to make up the connector I had to fabricate was the longest part of the entire process. But then such is often the way of marine repair tasks.

So here’s the picture-is-worth-a-thousand-words part. Before:


And after:


That’s all there was to it. But it made a huge difference in the operation of the water system. We should have done this a year ago!