BY GEORGE LANTHIER

Remember these questions from last time and did you find the answers?

What are the flow rates for most pipe sizes that would be used on a fresh water( potable) feed to a steam boiler, specifically ½” and ¾” pipe and at a working pressure of 55-60 psi? What is the average water content of a typical four section steam boiler for oil( about 135,000 Btus? How about the same boiler for gas?

The answer to the first question is that with a ½” pipe you can flow about 10 gallons per minute( gpm) and at ¾” you can flow about 16 gpm, that’ s forced pressurized flow, not heat transfer flow. The answer to the second question is that a typical 4 section, residential, steam, oil boiler, Figure 5-1, holds about 12 gallons of water to the“ working water line” and gas, steam boilers, Figure 5-2, hold about 9 gallons of water.

Now another couple of other questions? How long will it take at 10 gpm to fill an empty boiler to the working water line? In either case you’ re talking, at full flow, the ability to fill either boiler in about a minute and that’ s from empty! How long does it take to put in a gallon or two, well about 6 to 12 seconds, right?

So now we go back to the dilemmas. How do you fill that boiler slowly and how do you protect the boiler from overfilling both manually and automatically? As to the manual side we’ ll take a look at something you’ ve probably worked on and wondered about. Have you noticed that an awful lot of automatic water feeders for steam out there have 3 / 8” tappings, Figure 5-3? Those 3 / 8” valves have a very definite purpose, to control flow. You see a 3 / 8” pipe only has a flow rate of 6 gpm at 55-60 psi,

Figure 5-1

Figure 5-2

Figure 5-3

Figure 5-4

but a ¼” pipe only has a flow of 3 gpm at the same pressure. Ever have an older customer or someone with arthritis or other problem where opening and closing a globe or gate valve made refilling the boiler a big deal? Remember how good you felt by just putting on a ball valve for them? You looked like a hero because it was so much easier. Back in the day we all converted a bunch of people from the infamous # 14 blow down valve to a ball valve using a“ dirt pocket cap” and a nipple, today most just use something like the # 14B valve, Figure 5-4. So, no doubt about it everyone loves the ball valve, Figure 5-5. It’ s perfect for where you want a full open or full close valve and for drains or feeds the mighty valve ball is it! Now the trick is to use a ¼” ball valve instead of the usual ½” or ¾” size valve, Figure 5-5, with reducers, Figure 5-6. By doing that you limit, on a ½” system, the flow to just 3gpm. That’ s easier on the boiler and customer and greatly reduces shocking a hot boiler with really cold water in the winter. In addition, it makes it a lot harder for anyone to overfill the boiler quickly.

Figure 5-5

Figure 5-6

Finally, I’ ll bring back a couple of characters everyone seemed to enjoy and relate to so here’ s a memory with Bruce & Bubba from 1995. This has been one of our most requested articles.

Here’ s the story. Recently one of‘ Friendly Oil’ s’ customers had a boiler replaced. The installers put in a new steam boiler, adjusted all the controls, did a combustion test, and then left.

In the next three days they got seven service calls for erratic and insufficient heat.

After several of the oil company burnermen( hmmm), walk in, find the unit hot, the burner capable of running, and nothing wrong, the service manager gets steamed!

In desperation, the service manager of‘ Friendly’ s’ decides to get another opinion, and so he calls his old buddy Bruce.

But Bruce is very busy with a commercial burner problem and so he decides to send one of his techs, but this is not just another burnerman walking in, no way, it’ s Bubba and boy has he learned since we last met him. He now knows that the second Rule of burner service is‘ assume nothing’, and that the first Rule is‘ listen to the customer’.

After he arrives and gets in, here’ s what happens.“ Hi there, I guess you’ re having a problem with your new boiler”, asks Bubba.“ A problem, oh yeah, we’ re having a problem all right”, says the customer, Mrs. Nastybear,“ we spend three thousand dollars( 1995)

26 JANUARY 2026 | FUEL OIL NEWS | www. fueloilnews. com