Boiler Code Made Easy

Questtec Talks are back, this time with Hayden Laughter in the chair. Watch the video above on YouTube, or you can keep reading for a detailed synopsis of “Boiler Code Made Easy,” a Questtec Talk covering the big picture of what is required on a boiler vessel, designated by ASME Section 1 PG-60.

ASME Section 1 PG-60

PG-60 dictates all boilers that have a fixed water level (steam and water interface), shall have at least one gauge glass (a transparent device that permits visual determination of water level).

What is a gauge glass?

It is defined as a transparent device, which permits the visual determination of the water level per ASME Section 1 PG-60.

Types of Direct Reading Sightglass

• Reflex sightglass: continuous chamber (350 PSI working steam pressure and below). Above 350 PSI, condensate flow becomes too corrosive due to the higher working steam pressure.
• Transparent sightglass: overlapping visible
• Ported Bicolor Sightglass: ported continuous chamber (STB-3000). Caveat that this does not meet code unless the bicolor illuminator is part of the assembly.

What is not a direct reading sightglass?

• A magnetic level indicator: due to the fact that you’re not actually seeing the inter interface but you’re instead relying on a float, magnets, and the flipping of an indicator that is external to the process
• Conductivity
• Probe columns
• Guided wave radars
• DP transmitters

What are considered remote level indicators?

• Probe columns
• DP transmitters
• Magnetic level indicators
  • *Only if the transmitter is less than 900 PSI
• Guided wave radars

When are two gauge glasses needed?

When boilers have a maximum allowable working steam pressure exceeding 400 PSI they shall have two gauge glasses instead of one of the two required gauge glasses. Two independent remote water level indicators, two discreet systems that continuously measure, transmit, and display water level may be provided. When two independent remote level indicators are in reliable operation, continuously indicating water level, one required gauge glass may be shut off but shall be maintained in serviceable condition.

However, this leads to more maintenance time, man hours, and frustration that many end users don’t want.

Questtec’s Solution

We can ease the burden of meeting code for our customers by being knowledgeable on code so that we can step in and we can tell them what their different options are. But per all the requirements of code if they want to get away from having those two sightglasses that are constantly valved in, in operation, experiencing that constant corrosion that’s undergone by the condensate flow, they can instead implement either two probe columns and a guided wave radar or even a DP transmitter if they’re using some style of independent remote level indicator.

Questtec’s interpretation of best engineering practice is that you have a remote level indicator (probe columns, DP transmitters, guided wave radar, or magnetic level indicators under 900 PSI) in the control room independent of the DCS that is always on display.

So when you have customers that are dealing with issues with their sightglass and they’re frustrated with the constant repair, you can offer implementing two remote level indicators and one sightglass that may be valved out.

In Summary

There’s a pressure threshold at 400 PSI working steam pressure that we first assess. From there are more requirements and nuances, but this video and post should give you the overall big picture of solutions that Questtec can provide, by allowing end users to meet their requirements for ASME section 1 310.1, PG-60 and informing and updating our customers to help them better make a decision that will be best fit for their plant and their needs.

About Questtec

Questtec Solutions is an international company with representatives based around the world. Our Partners can assist with commissioning start up and calibration, 24-hour service, and repair support.

Questtec Solutions employs over 125 years of collective experience with all aspects of liquid level gauge and valve product lines. With a new state-of-the-art manufacturing facility and custom weld shop based in Houston, Texas, Questtec Solutions provides innovative engineered solutions to meet our customer’s specific needs.