In my last blog, we discussed the small PRVs that go on wet sprinkler systems to limit their pressure below 175 psi. That brought to mind a small PRV in another application that is used to keep something different cool: an electric motor-driven centrifugal fire pump. I can’t talk about electric fire pumps without also talking about diesel fire pumps, so let’s dive in and take a look at both! (more…)
Ah, summertime. Summer’s heat brings some good things: opportunities for outdoor swimming and seasonal produce: blueberries, and peaches, and watermelon…
Summer’s heat doesn’t bring all good things. It can even trigger issues with fire sprinkler systems. Let’s zoom in on a small component on a wet fire sprinkler system that’s there in part because of summer heating: a pressure relief valve.
A pressure relief valve (or an auxiliary air reservoir) is required on wet sprinkler systems; one reason is to (more…)
In Part 1, we looked at the basic parts of a fire sprinkler and took a closer look at other parts including heat responsive elements, wrench bosses, and kick springs. In this part, we’ll look at k-factors and deflectors.
K-Factor and Orifice Size
K-factor is a characteristic that relates water pressure to flow rate from the sprinkler, represented as k in the equation Q = k√P, where Q is flow (gpm) and P is pressure (psi).
If we supply water at 50 psi to a k-factor 5.6 sprinkler, the flow rate is 40 gpm. If we supply 50 psi water to a K25 sprinkler, the flow rate is 177 gpm. There are now sprinklers as large as K33.6, which would flow 238 gpm given 50 psi – big difference from the K5.6!
The most common k-factors are 5.6, 8.0, 11.2, 14, 16.8, 22.4 and 25. There are smaller and larger k-factors than these. For reference, K5.6 and possibly K8.0 are most often found in (more…)
In this blog we’ll take a look at the basic and some of the less-known parts of fire sprinklers, with more to come in a later post.
Here are the basic parts of the fire sprinkler, shown on a pendent glass bulb sprinkler and an upright solder element (“fusible link”) sprinkler:
Let’s take a closer look to learn about some of the less known parts, and also look at two types of sprinklers disassembled. Included in parentheses are some of the different names for some of these parts. (more…)