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Articles for NFPA

Name: ACS Valves
Address: 611 Argyle Street North, Caledonia, Ontario, N3W 1M1, Canada
Telephone: 1-905-765-2004
Price range: $

Apr 07, 2025 by Brittany Dollimore

Why keep spare valve parts on the shelf?
4 minute read
Stock extra rotary airlock valve parts on the shelf to reduce downtime, protect other important components, and keep your facility safe.
Feb 19, 2025 by Megan Thompson

What’s new in the NFPA 660 combustible dust standard?
4 minute read
NFPA 660: Standard for Combustible Dusts and Particulate Solids (2025) is now in effect. Find out what the changes mean for your processing plant.
Sep 09, 2024 by Megan Thompson

Is my rotary valve NFPA compliant?
3 minute read
Learn the requirements for an NFPA compliant rotary airlock valve and find out why compliance is so important.
Jun 20, 2024 by ACS Valves

6 ways to save time on rotary valve maintenance
4 minute read
Maintenance is non-negotiable, but it doesn’t have to cost hours of downtime. See our best tips for saving time on rotary airlock valve inspections, cleaning, and maintenance.
Apr 15, 2024 by Paul Bowman

How to: Check rotor-to-housing tolerances
3 minute read
Keep your rotary airlock valve compliant with NFPA guidelines and maintain strong performance by checking your rotor-to-housing clearances regularly.
Aug 10, 2023 by Greg Thompson

Protect your product: How outboard bearings keep valves safe
3 minute read
Why do we recommend outboard versus inboard bearings for rotary valves? It’s all about protecting your investments and your plant.
Jul 11, 2023 by Paul Bowman

How are rotary valves tested for safety?
3 minute read
To set you up for success, the ACS Valves team puts rotary airlock valves through some really rigorous tests.
Apr 14, 2023 by Megan Thompson

Quiz: What do you know about deflagrations?
6 minutes to complete
Deflagrations are a type of subsonic combustion, and they can pose a hazard to your processing facility. What do you know about them?
Feb 09, 2023 by Megan Thompson

Airlocks for dust collection systems: The basics
4 minute read
Everything you need to know about rotary airlock valves for dust collector applications
Jun 20, 2022 by Megan Thompson

Quiz: Workplace safety statistics to know
6 minutes to complete
See if you can guess these key stats from OSHA, NFPA, and other workplace safety organizations
Apr 22, 2022 by Megan Thompson

What is an NFPA compliant valve?
3 minute read
Find out if your rotary airlock valve is configured for optimal safety and NFPA compliance
Aug 18, 2021 by Megan Thompson

Choosing a rotary valve: 3 more things to consider
3 minute read
Find out how energy efficiency, NFPA safety and maintenance cycles impact your choice of rotary airlock valve
Jun 10, 2021 by Megan Thompson

Why should I keep a historical maintenance log?
3 minute read
Tracking maintenance helps you protect workers, keep equipment in good condition, and comply with NFPA regulations
May 07, 2021 by Greg Thompson

Check out the Multi-Port Valve, our latest invention
3 minute read
This one-of-a-kind rotary valve features multiple compartments for added efficiency in high-volume applications
Sep 18, 2020 by Megan Thompson

I missed the DHA deadline! What happens now?
4 minute read
The deadline for dust hazard analyses (DHAs) has passed, but you can still take steps to stay compliant with NFPA 652
May 20, 2020 by Megan Thompson

Why we recommend ACST-4 shaft seals for valves
3 minute read
Shaft seals are some of the fastest rotary valve parts to wear out. We’ll tell you which seal type has the most longevity and why
Apr 21, 2020 by Megan Thompson

Quiz: What do you know about DHAs?
6 minutes to complete
Industrial facilities need to conduct Dust Hazard Analyses (DHAs) by September 7, 2020. What do you know about the process?
Feb 17, 2020 by Paul Bowman

Are rotary airlocks supposed to leak?
3 minute read
The answer is yes… and no. Airlocks aren’t infallible, but there are ways to minimize leaks and keep air flow consistent
Feb 13, 2020 by Megan Thompson

Need a rotary valve safety guide?
less than a minute read
We published some comprehensive rotary valve safety guidelines in Powder & Bulk Solids
Jan 14, 2020 by Paul Bowman

Yes, you actually do need to check your rotor clearances
3 minute read
Measure your valve’s rotor-to-housing tolerances regularly to stay NFPA compliant and maximize material flow
Apr 24, 2019 by Megan Thompson

Pop Quiz: NFPA Valve Compliance, Part 2
5 minutes to complete
Here’s another test of your NFPA rotary valve knowledge. Are you ready?
Feb 21, 2019 by Paul Bowman

Flex or fixed? The difference between two rotor tip types
2 minute read
Find out which rotor tip type is right for your process
Jan 14, 2019 by Megan Thompson

Why choose a valve on rails?
2 minute read
Valves on rail systems deliver better ROI in several applications
May 22, 2018 by Megan Thompson

The ABCs of NFPA Valve Compliance
5 minute read
Key terms for your education on NFPA safety
Apr 24, 2018 by Megan Thompson

NFPA guidelines: Replacing your uncompliant parts
3 minute read
Stay safe and compliant with these rotary valve replacement tips
Feb 20, 2018 by ACS Valves

Pop Quiz: NFPA Valve Compliance
6 minutes to complete
How well do you know the NFPA rules as they relate to rotary valves?
Oct 04, 2017 by Megan Thompson

OSHA is sweeping combustible dust under the rug
4 minute read
Preventing dust explosions should be at the top of your agenda when planning plant safety, and we have the low-down on how to do just that.
Apr 25, 2017 by Nena Dallas

How to increase the life expectancy of your machinery
3 minute read
That rickety old valve has broken down again, and you're tired of replacing it all the time. Here are some tips on how to ensure your valves last longer and give you less downtime.
Jan 03, 2017 by Greg Thompson

How to use the same machinery for any material type
4 minute read
Replace your one-trick pony rotary valve with one that does it all
Jun 24, 2016 by Megan Thompson

Everything you need to know about NFPA 652
4 minute read
The NFPA has a new standard for combustible dust across all commodity-specific manufacturing industries worldwide. Find out what the standard includes and how to make your plant compliant.
May 25, 2016 by Megan Thompson

What you need to know about isolation devices
3 minute read
An explosion in your machinery doesn't have to lead to a plant-wide disaster. Read about ways to reduce the spread of flames with properly designed isolation devices and rotary airlock valves.
Apr 28, 2016 by ACS Valves

NFPA Safety: It's Not Just About the Airlock
1 minute read
On-demand one hour webinar on NFPA Safety.
Feb 26, 2016 by Megan Thompson

ACS deconstructs deflagration
3 minute read
Understanding the dangers of deflagration can help you better prevent plant fires and explosions.
Jun 02, 2015 by ACS Valves

Q&A with ACS
3 minute read
You asked. We answered.

Our live webinar on May 14, Understanding Airlocks, concluded with a lively Q&A session. In case you missed it, here are the questions you asked, along with our answers.

FAQs for NFPA

Q.
My conveying line handles dusty materials like cement or sand. How effective are rotary valves at minimizing dust leakage?

A.
Rotary valves can be very effective at minimizing leakage when properly configured by an expert.

As a general recommendation to prevent dust leakage, valves should be equipped with ACST-4 shaft seals and an outboard bearing design. You should also check rotor-to-housing tolerances often, as enlarged tolerances can also cause leaks.
Q.
Which parts of a rotary valve do I need to replace?

A.
The most common parts you need to replace on a regular basis include the rotor, shaft seals, and bearings. It’s a great idea to keep spare parts for your rotary valve. We have an NFPA compliance kit you can order to have the most important parts on your shelf just in case you need to make a quick replacement.
Q.
Why do I need to check rotor-to-housing tolerances?

A.
Rotor-to-housing tolerances, or clearances, are the distance between your rotor tips and valve housing. Because they wear down over time, you should measure them as part of your regular maintenance routine. Increased tolerances leave a bigger gap for material to leak through, which prevents the valve from working effectively. This can lead to issues with material flow, NFPA compliance and safety, and overall efficiency. Check them often!
Q.
My valve is losing too much air, what could be the problem?

A.
Too much clearance between the rotor, endplates and or housing can result in air loss. Measure the rotor to endplate and rotor to housing clearances to confirm that they are an NFPA compliant 0.0079 inches. If the clearance is larger than this, it might be time to replace your rotor, rotary valve, or have it sent back to ACS for a repair or evaluation. Make sure to stick to a maintenance schedule and check your clearances at least every three months.