Grooved FAQs

Grooved FAQ Document August 2022

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Q:          Is Reliable grooved compatible with other manufacturers’ grooved products?

A:           Reliable grooved products use the same AWWA C606 grooved standard common with most grooved products.  Any grooved product manufactured to this common standard should be compatible with Reliable grooved products.

Q:          Is Reliable grooved qualified on proprietary Sch 7 sprinkler pipe?

A:           Yes, we have worked with UL and FM to expand qualifications for coupling products beyond just Schedule 10 and Schedule 40 pipe to include:

  • Youngstown Tube Fire-Flo
  • Wheatland Tube Mega-Flow
  • Bull Moose Eddyflow
  • Nucor Hydroflow

Our product-specific technical bulletins contain details on pipe qualifications for every gasketed fitting. Reliable’s bulletins are constantly updated to reflect changing industry trends, evolving customer needs, and expanded 3rd party qualifications to ensure we deliver what our customers expect and need.

Q:          Are the coupling gaskets pre-lubricated?

A:           There are two types of pre-lubricated gaskets; a surface treatment applied to finished gaskets prior to coupling assembly (typically a white powder) or embedding a lubricant in the rubber mixture itself before molding so that it “blooms” out naturally. Reliable grooved couplings use both types of pre-lubrication, providing a double advantage to users of Reliable Grooved.

Q:          How do the Reliable grooved elastomer options compare to competitor products?

A:           We focus on using a standardized single elastomer type that is the most common in fire protection products, EPDM rubber. Most EPDM rubbers are very similar, and the specific chemistries provided by our manufacturing partner are fit-for-purpose for a grooved fire protection system application. The temperature range for our EPDM rubber is annotated in our product-specific technical bulletins; an end-user should evaluate the specific requirements of their application and municipality regulations to determine if our UL / FM qualified temperature range is appropriate. All gaskets are qualified by UL and FM just like our competitor’s products, so you can be assured that our grooved products will perform the same.

Q:          Are the takeout dimensions of grooved fittings and couplings the same as other grooved manufacturers?

A:           Some products (depending on the model number and NPS) use identical takeout dimensions, while others are slightly different. Most of the takeout dimensions that are not identical across the various brands are close enough that they should not impact installation; however, a qualified and experienced installer should review the takeout dimensions and assess any compatibility issues with Reliable grooved products.

Q:          Can I use two halves of a mechanical tee to make a mechanical cross?

A:           FM and UL require specific qualifications to utilize these products in this way; at this time, RASCO is not qualified for this configuration. While the products are physically capable of being assembled in this configuration due to the design of cast components, they lack FM and UL qualification in this configuration should be considered against industry and municipality requirements before installing in this configuration; and is not recommended.

Q:          Are u-bolt mechanical tees approved for use on branch lines, or just sprigs and drops?

A:           This is a complicated question to answer. FM allows the use of u-bolt mechanical tees with 1” outlets for connecting branch lines, but UL requires additional testing that has not been performed for Reliable u-bolt mechanical tees. If an installer wishes to use a u-bolt mechanical tee with a 1” outlet to connect a branch line, the lack of UL-qualification in this application should be considered by a competent technical authority. Reliable’s recommendation is that a conventional mechanical tee (MTT2 or MTG1) be used for branch line connections, as these products in all sizes are qualified for this type of use.

Q: My 1-1/4” x 1-1/2” RCD Reducing Couplings do not have a metal ring.  Is this a problem?

A:  Most sizes of RCD Reducing Couplings use a metal reinforcing ring to provide additional support to the gasket that allows it to resist pressure and maintain a seal.  The need for this reinforcing ring is dependent on the size difference between the two sides of the reducing coupling.  For the 1-1/4” x 1-1/2” size, the outlets are so close in size that a metal reinforcing ring is not necessary, and all UL / FM qualification testing has been performed without one.  The product is fit-for-purpose without the metal ring and can be installed just like any other grooved coupling.

Q:          I’m having difficulties with Reliable grooved installation; what do I do?

A:           Grooved couplings are sensitive to correct installation across all manufacturers and brands. The most common issue is uneven application of torque to the nuts, which results in pinching of the gaskets. If a coupling is demonstrating a leak, loosen and re-tighten the nuts in accordance with the Reliable grooved installation guide available on our website. Also, ensure that the coupling is properly seated in the grooves and that pipe ends do not have substantial damage or deformity that could impact the performance of the coupling gasket. Reliable technical support is available through our Technical Services Department to help customers resolve any challenges with Reliable grooved products.

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Do you have a technical product question? Contact our technical services team to get the answers you need to move your project forward.

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