Statement of Compliance – NFPA 69 & 85 Standards

PMM’s Close-Tolerance Rotary Valve Airlocks are engineered to meet the requirements outlined in the relevant
sections of the NFPA 69 Standard on Explosion Prevention Systems and the NFPA 85 Boiler and Combustion Systems Hazards Code (2019 version).

PMM’s Rotary Valve Airlocks are the perfect addition to any material handling system when and where safety is of the utmost importance!

These standards provide important guidelines and regulations for the safe operation of Close-Clearance Rotary Valves operating within industrial manufacturing material handling systems.

NFPA Frequently Asked Questions

The NFPA (National Fire Protection Association) is a non-profit organization that is dedicated to promoting fire safety and prevention. The purpose of the NFPA is to develop and publish codes, standards, guidelines, and best practices to reduce the risk of fire-related hazards and improve overall safety in various settings.

By integrating Precision Machine & Manufacturing’s NFPA compliant components into a material handling system, PMM’s customers can benefit from enhanced safety, reduced fire risks, and improved overall operational reliability.

When a product or system is referred to as “NFPA compliant,” it means that the company making the statement believes that the component, system, and/or operation meets the specific requirements outlined in the applicable codes, standards, and guidelines developed by the National Fire Protection Association (NFPA). These requirements are designed to promote fire safety and prevent fire-related hazards in various settings.

Important Note: Any certification or other statement of compliance with the requirements set forth by the NFPA shall not be attributable to the NFPA and is solely the responsibility of the certifier or maker of the statement.
• Reference: NFPA 69, page 1, IMPORTANT NOTICES AND DISCLAIMERS CONCERNING NFPA STANDARDS

NO! Although the NFPA administers the standards, guidelines and/or rules, the NFPA DOES NOT INDEPENDENTLY TEST, EVALUATE, and/or VERIFY the accuracy of any information or the soundness of any judgments contained in NFPA standards. Nor does the NFPA list, certify, test, or inspect products, designs or installations for compliance with the NFPA Standards. In addition, the NFPA has no power, nor does it undertake, to police or enforce compliance with the contents of the NFPA Standards. Nor does the NFPA list, certify, test, or inspect products, designs or installations for compliance with the NFPA Standards.

  • Reference: NFPA 69, page 1, IMPORTANT NOTICES AND DISCLAIMERS CONCERNING NFPA STANDARDS

The responsibility for confirming and self-certifying compliance with NFPA guidelines lies with the manufacturer, engineering firm, systems designer, builder, or any other entity involved in the design, manufacturing, or implementation of components, systems, or processes. These entities are responsible for ensuring that their products or systems adhere to the guidelines and specifications established by the NFPA.

When a company claims that a specific component or material handling system is “NFPA Compliant,” it generally means that they have manufactured the product or system according to the guidelines outlined by the applicable NFPA standards.

  • It is essential for the end-user to exercise independent judgment and if necessary, seek the advice of a competent professional in determining whether the products, systems, or processes being installed and operated comply with the specified guidelines, codes, and statutes of the applicable NFPA codes.
  • Ultimately, the responsibility for ensuring NFPA compliance and safe operation rests with the end-user.
  • The NFPA as well as Precision Machine & Manufacturing disclaims liability for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential or compensatory, directly or indirectly resulting from the publication, use of, or reliance on NFPA Standards.

NO! Neither the NFPA or Precision Machine & Manufacturing are liable for any damages resulting from an explosion or fire related accident.

The NFPA and Precision Machine & Manufacturing, specifically disclaims liability or responsibility for any personal injury, property, or other damages of any nature whatsoever, whether special, indirect, consequential, or compensatory, directly or indirectly resulting from the publication, use of, or reliance on NFPA Standards. The NFPA and Precision Machine & Manufacturing also makes no guaranty or warranty as to the accuracy or completeness of any information published herein.

  • Ultimately the responsibility rests solely with the end-user and/or operator.
  • Reference: NFPA 69, page 1, IMPORTANT NOTICES AND DISCLAIMERS CONCERNING NFPA STANDARDS.

In the realm of rotary feeder, rotary valve, and airlock manufacturing, as well as their operation within material handling systems, the NFPA 69 Standard and NFPA 85 Code are commonly referenced.

• NFPA 69 provides specific information related to rotary valve manufacturing.
• NFPA 85 contains guidance for the operation of rotary valves within material handling systems, particularly those used in boiler and combustion systems.

Both NFPA 69 and NFPA 85 play important roles in promoting safety and preventing hazards associated with rotary valves, rotary feeders, and/or Airlocks in material handling systems. They provide comprehensive guidelines and requirements that manufacturers, engineering firms, and end-users can reference to ensure compliance with recognized industry best practices.

NFPA standards are extremely challenging, and although some manufacturers may be able to achieve several of specifications outlined in the relevant NFPA subsection, achieving 100% compliancy can be an extremely difficult task, which is why there are only a handful of OEMs who manufacture NFPA compliant rotary valves.

A few of the more difficult subsections that rotary valve OEMs struggle to achieve are directly related to the design considerations and criteria as outlined in:

  • NFPA 69 12.2.4.1, 12.2.4.2 and 12.2.4.5, and built with sufficient strength to withstand “explosion pressure” 12.2.4.3.1, as well as with no structure deflection or deformation 12.2.4.3.3.

These are extremely difficult standards to achieve and when combined with subsection 12.2.4.3.3 “certified or tested by a knowledgeable test authority,” and combined with the relevant subsections outlined in NFPA 85, most OEM’s are simply not able to get their product(s) completely across the finish line.

Most companies are quite vague about how their rotary valve and/or airlock complies with the NFPA Standards and Codes. It is for this reason, why Precision Machine & Manufacturing took the time to specifically list all of the relevant NFPA standards and subsections (see below) relating to Rotary Valves, Rotary Feeders, and Airlocks and very clearly provides the information relating to how Precision Machine & Manufacturing’s rotary valves meet or exceed each NFPA subsection.

  • We believe in transparency, which is why we are the first rotary feeder manufacturer to take the time and outline each of the relevant NFPA subsections and how PMM’s rotary valves are compliant.

NFPA 69 – Standard on Explosion Prevention Systems (2019)

Standard
12.2.4.2

Relevant Section: Chapter 12 Deflagration Control by Passive Isolation Rotary Valve Design Criteria
PMM NFPA Compliance: PMM Rotary Valves are designed per “close clearance valve” specifications as outlined in NFPA 69, subsection: 12.2.4.5

Standard
12.2.4.3.1

The valve body and rotor shall have sufficient strength to withstand the maximum anticipated explosion pressure.
PMM NFPA Compliance: PMM Rotary Valves have a design pressure of 14.9 psi.

Standard
12.2.4.3.3

The valve pressure resistance shall be verified or tested by a knowledgeable test authority.
PMM NFPA Compliance: PMM Rotary Valves have been tested by an independent authority and tested up to 50 psi, with no structure deflection or deformation.

Standard
12.2.4.3.4

There shall be at least six vanes on the rotary, diametrically opposed.
PMM NFPA Compliance: PMM Rotary Valves are equipped with eight vanes, which are all diametrically opposed and have at least two rotor touching the housing at all times.

Standard
12.2.4.3.5

At least two vanes on each side of the valve housing shall be in a position of minimum clearance at all times.
PMM NFPA Compliance: PMM Rotary Valves are constructed to ensure that at least two of the valve’s eight vanes are in contact with each side of the barrel (housing), at all times.

Standard
12.2.4.3.6

The valve shall have metal body and vanes unless it is shown by best data that nonmetallic or composite materials prevent flame passage.
PMM NFPA Compliance: All PMM Rotary Valves contain a metal body and rotor. Each is manufactured from a specialty through hardened, 500 Brinell abrasion-resistant steel alloy, which is ion-nitride surface treated to obtain a hardness rating of 62-64 Rockwell.

Standard
12.2.4.3.7

Rotary valve bearings shall be mounted externally.
PMM NFPA Compliance: All PMM Rotary Valves are equipped with heavy-duty, outboard tapered roller bearings. 

Standard
12.2.4.5.1

Close-clearance rotary valves shall be designed with a clearance between the vane and the valve body less than or equal to 0.2 mm (0.008 in.)
PMM NFPA Compliance: As a “Close-Clearance Rotary Valve,” the PMV & PMK Rotary Valves are sized for minimal airflow thanks to the industry leading .005” minimum rotor to barrel (housing) clearance.
-SIZING INFORMATION: All PMM Rotary Valves are sized according to the operational material and environment temperature of the application where the rotary valve will be placed.
-Depending upon the operational temperature, the clearance at startup might be slightly larger/smaller to allow for the precise amount of rotor swelling/shrinking while also achieving the closest rotor to barrel clearance possible.

Standard
12.2.4.5.2

The clearance between vane and valve body shall be small enough to prevent the passage of flame between the rotor and the valve housing.
PMM NFPA Compliance: PMM Rotary Valves are manufactured per a specialized proprietary process, which allows for the tightest possible clearance between the rotor and housing, while still allowing the rotor to turn.
-Please note: No rotary valve is 100% air-tight, and although PMM’s industry leading rotary valves do posses the tightest possible rotor to housing clearance among all rotary valve manufacturers, minimal space is necessary to enable turning of the rotor.

Standard
12.2.4.5.3

Actual clearances of such rotary valves shall be measured before installation and monitored using a predictive maintenance program such that the design clearance is not exceeded due to wear.
PMM NFPA Compliance: All PMM Rotary Valves are shipped from the factory with the precise amount of clearance to meet the operational temperature of the environment.
-Please note: It is the responsibility of the end-user/operating company to ensure deployment of a comprehensive preventive maintenance program, which occurs at specific intervals, preferably every 3-months at a minimum, includes measuring and monitoring rotor to housing clearances, and is capable of making adjustments and/or replacing worn components when necessary.
-Please note: When the rotary valve is received, the actual clearances may be slightly larger/smaller. This is to allow for expansion or shrinkage do to the environmental temperatures of the application where the rotary valve will be operating.

Standard
12.2.4.6

Rotary Valve Application Limits: Rotary valves shall not be permitted to be used as an isolation device for systems handling hybrid mixtures or gases.
PMM NFPA Compliance: WE AGREE! Here at PMM, we do not endorse the use of PMM Rotary Valves as an isolation device in these types of applications.

ANNEX A
A.12.2.4.5

Testing has shown that rotary valves can be effective in isolating explosion propagation if the following conditions are in place:
(1) There are three vanes on each side of the valve that are diametrically opposed.
(2) A close tolerance is maintained between the vanes and the valve body, less than or equal to .008”.
(3) Two vanes per side are always in contact with the housing
(4) The vanes or tips are made out of metal and have a thickness of at least .12” PMM NFPA Compliance: PMM Rotary Valves meet the specifications at outlined.

NFPA 85 – Boiler and Combustion Systems Hazards Code (2019):

  • Chapter 9 – Pulverized Fuel Systems
  • Please note: Although PMM Rotary Valves are compliant with a variety of NFPA 85 standards, the Pulverized Fuel System standard encompasses the majority, if not all the relevant compliance points.

Standard
9.1.3

Covers pulverized fuel systems designed to reduce fuel to a size such that at least 50% will pass through 200-mesh (74 micron) sieve.
PMM NFPA Compliance: PMM Rotary Valves are manufactured per NFPA 69 standards, which is applicable in various NFPA 85 codes referencing boiler and stoker applications.

Standard
9.3.6

Where used as a means for deflagration isolation, rotary valves (material chokes) shall be installed and maintained in accordance with NFPA 69.
PMM NFPA Compliance: PMM Rotary Valves are manufactured per NFPA 69 standards.

Standard
9.4.3.2.2

All components of the raw fuel feeder system shall be designed to withstand an internal deflagration without rupture.
PMM NFPA Compliance: PMM Rotary Valves have been tested by an independent test authority up to 50 psi, with no structure deflection or deformation.

Standard
9.4.3.2.7.1

All valves in the raw fuel feeder system shall have construction capable of withstanding pressures as defined in 9.4.3.2.2.
PMM NFPA Compliance: PMM Rotary Valves have a design pressure of 14.9 psi.

Standard
9.7.3.3.2.1

Special dust tight valves shall be installed at each fuel outlet of the pulverized fuel bin, the fuel discharge outlet, and each fuel outlet of the pulverized fuel distributors.
PMM Rotary Valves have a long and proven history of operating in dust collection and dust prevention applications.

NFPA Compliant
Rotary Valves

Heavy-Duty

Modular Rotary Valve

NFPA 69 & 85 Compliant

Heavy-Duty

Rotary Valve Airlock w/ Knife

NFPA 69 & 85 Compliant

Heavy-Duty

Self-Cleaning Rotary Valve

NFPA 69 & 85 Compliant