Bad Spray Equipment Design Leads To Tank and Pump Troubles

We’re going to get a bit technical here but, it’s because we are spray equipment experts. We stay up late at night thinking of problems and how you’d have to deal with them when we design rigs for our clients spray equipment. Thankfully, we see a lot of terrible design ideas to teach us what NOT to do when they come in for help! This is a favorite – they did put thought into this tank actually, but they could have done better.

First, we suggest suction at the top or bottom of commercial lawn spray equipment tanks, toss out this middle of the tank nonsense, please! They did put on a shut off valve which is a step in the right direction but, it’s all connected to plastic, that is just waiting to dry up and break. The heat of the summer sun will do a number on that plastic and with one crank it could all snap! 

On to the main topic though, the pump! In this picture we can see they decided to use their pressure relief line as an agitator into the main tank. You can’t put a shut off valve on that or it will blow up when you release the trigger. So, what happens when you have to service this pump? You have to dump your tank because it’s going to drain to the lowest point! It’s water, it finds level.

We recommend pressure relief on the top of tanks because water can’t drain up. Agitation at the bottom where you can place a shut off valve. Our whole point is good design will save you time, save you money and increase profitability. 

Andrew Greess: Here's another one. Oh, this is amazing. I can do an hour on this photo alone. Let's look. A couple of things. Here's another one. Tanks have suction either at the top or the bottom. Some people like top suction, some people like bottom suction. I like bottom, but there's pros and cons to both.

This is middle tank suction. There's nothing good about this, but it's the same thing. It's all plastic. They do have a shut‑off valve right here, but it's all plastic. If you go to turn this shut‑off...See the shut‑off valve? There's the yellow handle. You go to turn this shut‑off valve, you're going to snap some of this plastic. That's not even what I want to talk about.

Most of the pumps that we use are what's called positive displacement pump, which means, when you let go of the trigger, the water goes back into the tank through the pressure relief valve. You guys familiar with what I'm talking about?

You can't put a shut‑off valve on that pressure relief line because, if you did, when you let go of its spray trigger, it's going to blow up. You have to have that pressure vent back into the tank. What this company did was, they put that pressure relief line into the bottom of the tank and put a jet agitation on it.

They're trying to be clever, trying to save a little money, "We're gonna use our return as agitation." What that means is you can't put a shut‑off valve on this line. Because you can't put a shut off valve in this line, what that means is you can't service this pump when the tank is full.

If you take the pump off or disconnect the pump, 50 gallons are going to drain right out of there because there's no shut‑off valve. Does that make sense? It's a little technical, but it's really important.

To save a few dollars on agitation, instead of doing agitation right...The way you would do this right would be you'd have the pressure relief go into the top of the tank. You don't need a shut‑off because it's not going to drain up.

Then you have agitation at the bottom of tank, and you can put a shut‑off valve on agitation because you still have pressure relief in the top. It's a little technical, but it's really important. Anyone following what I'm saying here? This is stuff people don't look at. That's an important one because when is your pump going to need service?

Your pump doesn't need service when you're not using it. You need service when your tank is full, and you're using it. You have two options here. You can either dump 50 gallons or you can keep using your pump even though it needs service, which means you're going to probably do more damage to it. Really bad design.

When I talk about good design, what do I mean? Here's a sprayer we built. Had three tanks, three pumps, three motors and four house reels. We want to be able to get to...See all these pumps and motors? They're raised so you can change the oil, and they're all easy to get to.

They're all easy for service. You want to make sure your stuff is easy for service, and they're also easy to start. Really good design.

If you missed any of the videos in this series, catch up on them here:

Experience Pays: Top 10 Avoidable Spray Equipment Problems And Ways To Avoid Them

Choosing the Right Spray Equipment Engines, Backpacks, Pumps and Trailers

Spray Fittings and Tanks - The Right Small Spray Equipment Components Matter Too

Oh The Hose Reel Problems We’ve Seen!

Cut Out Design Flaws and Down Time with Better Spray Equipment Design

Common Sense Missing in Some Backpack Sprayers

Avoid Problems By Consulting Experts in Their Field

Bad Design = More Work And Money in Repairs

Need Easy Access to Spray Equipment Filters

For more information on Andrew Greess, visit https://www.qspray.com/