Grooved FAQs

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Grooved FAQ Document August

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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.

Grooved mechanical piping has been changing the way contractors do business for more than 85 years, but this method of pipe joining is still unknown or misunderstood in some areas of the commercial building industry. Many other pipe joining methods exist for mechanical piping systems, particularly in HVAC and plumbing applications. What some contractors may not realize are the opportunities that grooved mechanical piping provides in terms of increased profits, compressed schedules, and worksite safety.

Many of the benefits of the grooved coupling are inherent in the physical design of the product, which is why it is important to understand the grooved concept and the features of the product.

A grooved pipe joint is comprised of four elements: the grooved pipe, the gasket, the coupling housing, and the nuts and bolts. The groove is made by cold forming or machining a groove into the pipe ends. A gasket encompassed by the coupling housing forms a seal on the two pipe ends, and the key sections of the coupling housing engage the grooves. The bolts and nuts are tightened with a socket wrench or impact wrench. In the installed state, the coupling housing encases the gasket and engages the grooves around the circumference of the pipe to create a leak-tight seal in a self-restrained pipe joint. There are two basic coupling styles that can be used on grooved pipe: flexible and rigid.

&#; Flexible couplings allow a limited amount of linear and angular movement.

For more fire fighting pipeinformation, please contact us. We will provide professional answers.

&#; Rigid couplings do not allow movement at the joint.

There are a number of benefits to choosing grooved mechanical piping where applicable.

Benefits of Grooved Mechanical Piping

Recent product enhancements by grooved coupling manufacturers have significantly increased installation times. Unlike standard couplings, installation-ready couplings are installed without the need to disassemble the coupling. No loose bolts and nuts translate to less material handling on site.

Unlike welding, brazing, or soldering, grooved mechanical pipe joints do not require a flame or fire watch, and as a result, assembling and disassembling of a pipe joint is fast and easy. Pipe fitters install grooved mechanical pipe joints properly and accurately with minimal training and no additional safety measures.

The design of grooved systems allows for easier routine and scheduled maintenance because the grooved coupling provides a union at every joint, which permits easier access to the system.

Removing a coupling is easy; the worker loosens the nuts and bolts and removes the coupling housings and gasket. Once maintenance is complete, the coupling can be reassembled on the grooved end of a pipe, valve, fitting or accessory.

Because maintenance does not require torches, grooved systems do not have to be completely drained and dried to perform the maintenance, resulting in minimal system downtime. A grooved system not only offers a union at every joint, which simplifies system access, but a grooved system offers 360 degrees of rotational movement during installation, reducing field mate-up issues by making it easy to perform adjustments on site.

The design of grooved couplings, which are secure and leak-tight, make them very reliable. Couplings require no maintenance and are designed to last the life of the piping system. Grooved mechanical piping systems can be pressurized and depressurized repeatedly for years without ever fatiguing the elastomer gasket.

Labor time is the largest cost variable in the field, and grooved systems offer a reduction in total installed costs because they reduce labor time. The ease and speed at which grooved mechanical piping systems are installed allows contractors to positively impact the bottom line and meet stringent project schedules.

Thermal transients may impose deflection on a piping system as the pipe grows when heated and contracts when cooled, resulting in stress on the piping system and equipment. Flexible grooved couplings minimize this stress by allowing limited deflection capabilities to accommodate this movement in system offsets or for use in expansion loops. As an added benefit, flexible couplings allow angular flexibility to accommodate piping misalignment and rotational movement for use in seismic swing joints.

Mechanical room equipment frequently creates noise and vibration which needs to be isolated from the piping system. Flexible mechanical systems allow the pipe to move within the grooved coupling and the elastomeric gasket dampens vibration, thereby localizing the vibrations generated by equipment and reducing the amount of noise transmitted down the pipeline. The design of the mechanical joint performs this function without wearing out the gasket.

Grooved piping technology&#;s inherent qualities naturally make it environmentally friendly. It significantly reduces or eliminates waste, emissions, and noise pollution on the job site. Weld and X-ray machines are not required which reduces the draw on burdened power resources. The indoor and outdoor air quality is preserved because the joining method does not release fumes or particulate matter.

For more information, visit www.victaulic.com.

Publication date: 3/19/ 

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