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Relief Pitching

Updated: Jul 23, 2018

Let's talk about relief valves today. Why? They're bright blue and caught my attention on one of my photo-taking excursions, what else do you need there?

Okay, that wasn't the only thing. When you're coming into something (the entire oil and gas industry, just to name an example that applies to some random person who totally isn't me) with zero prior knowledge, you learn to always look for clues that will help you do some further research. A lot of times, a manufacturer's name stamped on the thing is enough to at least get started. This fortunately has that, as it's made by a company called Fulflo, which Google tells me is located right here in Ohio - down in a rural town called Blanchester, about 40 miles northeast of Cincinnati. There's way more than that too: a part number.

One thing that's really kind of cool, with a lot of this stuff, is how much meaning is packed into part numbers. For example, I happen to know that our gauge numbers here at Summit Sales include seven pieces of information - things like dial size, PSI range, and connection type and location, to name some of them - in a ten-digit part number. It's not really any different with the folks at Fulflo. Let's take a look.

So this is what we have to work with (you're welcome for flipping it upside down), and hey, there's a Fulflo catalog online that explains all of it. Nice. I'm going off of page 13, if you want to follow along.

V: The series identification. I won't get fully into the different lines Fulflo offers but this bit of information tells you a lot in and of itself as well, for example that "the V-Series valves are ideally suited in hydraulic and lubricating systems for load regulation and system protection." Sounds about right.

J: It's made of cast iron...

5:'s the 1" size...

R: has buna o-rings...

SP: ...and steel parts.

The subsequent lines are pretty much optional add-ons. The "SS" for 416 stainless steel pistons, while the "XS" defines the spring used. So there you go, if one of these things ever falls in your lap, without anything but the outer casing, you'll be okay.

So what do they do? First off, here are the guts.

Since I cut off the label key: I is a piston, G is a spring, A is the body, B is the cap, C is an adjusting screw, most of the rest are various o-rings and gaskets.

I know I saw this every time, but the simplistic genius behind so many of these parts is so completely mindblowing to me - in fact, this will only take like three sentences to explain.

Fluid enters through the "in" hole on the bottom there. It then meets that spring-loaded piston there, and fights against the pressure it offers. Eventually, the entering fluid overcomes the spring and is able to exit through the side hole but at a reduced and safer pressure, as the spring absorbed some part of that initial energy.

The general layout of the thing is not entirely different from the diaphragm protectors we talked about on here a little bit ago, with the obvious key difference that these are absorbing some of the pressure while the diaphragm protector seeks to maintain pressure for an accurate gauge reading.

There's a lot more engineering behind them (both of them, really) if you want to pursue a deeper level, trust me, I tried to read the words in that catalog, but that's the basic overview. Pretty neat.

Here's one in context, moderating the oil lubrication system around the power end, which is pretty much the typical place to see this specific variety in our world - there are plenty of other types of them of course, including ones that help regulate the primary flow through the other side of the pump.

Zoom out a little? Sure. You might recognize this vehicle. And the more astute observers among you may also notice that I did not take these photos at the same time.

It shouldn't really be surprising - because where else would it come from - but that line, after passing through that filter on the left edge of the photo, ends up all the way in the front of the truck.

By the way, guess what we have lying around? I didn't even need to go to the warehouse for this picture, they're in a room about ten feet away from me that we use to store some of our smaller parts.

Our part number has some meaning too, of course. Obviously we borrowed the VJ and the 5R from theirs, "FF" for the supplier, and the leading numbers correspond with different part categories that we have.

But, more importantly, contact us if you need one. Mention this blog post and I'll go back, grab it off the shelf, and deliver it in person if you're in the Shale Crescent region, that's how much it means to me.

See you soon?

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