Sizes 5-1/2, 6 and 7 not available in shrouded bolt.
F 1 through F 7
Rigid couplings, which are in some cases called sleeve or muff couplings, have been historically imprecise, economical, and frequently homemade segments for a straightforward shaft to shaft associations.
In the past, numerous individuals would not think about utilizing a rigid coupling in any servo application.
However, littler estimated rigid couplings, particularly made of aluminium, are progressively being utilized in movement control applications because of their high torque limit, firmness, and zero kickback.
Rigid couplings are torsionally stiff couplings with for all intents and purposes zero windups under torque loads. In the event that any misalignment is available in the framework, the forces will cause the shafts, bearings or coupling to flop prematurely.
Rigid couplings can’t be kept running at very high rpm’s for the reason that they can’t adjust for any thermal changes in the shafts which are brought about by the high-speed use.
In any case, where misalignment can be firmly controlled rigid couplings offer excellent performance characteristics in servo applications.
An occasionally overlooked advantage of rigid couplings is they can be utilized to build up shaft alignment in misaligned systems. To build up shaft alignment the engine and segment mounts should be relaxed to guarantee there is free development.
Then connect the shafts with the rigid coupling which, if accurately made, will adjust the shafts. In conclusion, focus the segments on any staying free play and fix the mounts.
Rigid couplings clamp onto and join two shafts, influencing them to work as one, yet unlike too many coupling types, don’t accommodate for misalignment.
Rigid Couplings are offered in many different designs, with or without keyways, for connecting supported shafts. One-piece designs are slip over the shafts ends closely and are bit by bit and successively clipped by fixing the bolts.
This enables the coupling to “seat” on the shaft. Working also to the one-piece plan, two-piece clamp couplings can be assembled anywhere and any point of time because they come apart without mechanisms and tools.
Three-piece plans can likewise be introduced anywhere, however, they can likewise remain gathered on one shaft while they are dismantled from the other.
Read More: Evolution of Gear Couplings
Required features for Motion Control
There are a few highlights expected of rigid couplings to guarantee appropriate execution in motion control applications.
The most vital component is that the coupling itself does not bring misalignment into a system where it can’t be retained without harm to course and seals.
The strictest control of shaft arrangement will result when the bores are honed, since honing guarantees that the two bores are collinear. Sharpening additionally amends any remaining bends brought about by stresses presented amid the assembling procedure, bringing about around, decisively estimated bore.
Proper sizing and geometry guarantee a large level of shaft contact and more prominent torque transmission capacity.
Read More: Applications of Spider Star Jaw Couplings
Proper Installation and Special Design
Most clamp-style rigid couplings have been structured with cap bolts near each other and masterminded in sets.
Particularly when joined with a cross-cut, this design facilitates encourages more prominent holding power and furthermore obliges slight deviations in the span of the two shafts being associated.
It is suggested that this style of coupling be introduced by fixing the combined fastens then again a few stages. This is on the grounds that the nearness of the bolts results in a commonality of the circle pressure created in the coupling by each screw in a pair.
As each bolt is fixed it will, in general, loosen up any strain created by its companion. On the other hand, fixing the bolts a few stages appropriate the strain all the more equally, guaranteeing a more tightly fit and the ideal holding power.
There are many types of coupling available in the market having its own importance in different parts of the transmission.
Rathi Couplings provides every type of power transmission coupling and have a range of products. Lovejoy couplings are one of the best coupling manufacturers with products ranging from pin bush couplings, fluid couplings and spacer couplings.
Products
Couplings, Flexible Shafts & Universal Joints
Couplings, Flexible Shafts & Universal Joints
Couplings are devices used to connect two shafts together and are divided into two categories: Rigid and Flexible Couplings
Both flexible and rigid couplings are used for the purpose of transmitting power. However, rigid couplings are limited in comparison to flexible couplings. Flexible couplings are designed to accommodate: angular misalignment, angular offset, axial movement, and various types of load conditions. Rigid couplings are used where shafts are already positioned in precise lateral and angular alignment. Their rigid design does not allow for any misalignment between shafts, but they are generally able to transmit more power than flexible couplings.
With many styles and types of couplings available, your application conditions must be clearly understood. ...Our experienced engineers can solve even the most difficult application issues and find the right coupling solution for your application. SDP/SI offers a wide variety of both rigid and flexible couplings. Many of our precision couplings are designed with our unique Fairloc® Hub design, including the Miniature Fairloc® Bellows Coupling and the Neo-Flex Coupling. Modular Bellows Couplings can be configured to accommodate various shaft diameters and provide backlash-free torque transmission. Magnetic Disk Couplings are built to handle up to 3° of angular offset and operate in temperatures up to 284°F.
Flexible Shafts can be used in applications where the load must be moved in many directions. Flexible Shafts are stiff in torsion and very compliant in bending and lateral misalignments. They are extremely useful where the load is located in a remote position requiring many gear and shafting combinations. The basic design considerations are torque capacity, speed, direction of rotation, bend radii and service conditions.
Metal and Molded Universal Joints
Universal joints are used to transmit power, motion, or both. Cardan joints or Hooke joints are the most common and consists of two yokes, one on each shaft, connected by a cross-shaped intermediate member called the ”spider”. The angle between the shafts is called the operating angle. It is usually constant during operation, but not necessarily so. Good design practice calls for low operating angles, often less than 25°.
Universal joints are available in steel or in thermoplastic body members. For maximum load-carrying capacity, for a given size, a steel universal joint should be selected. Universal joints with thermoplastic body members are used in light industrial applications in which their self-lubricating feature, light weight, negligible backlash, corrosion resistance and capability for high-speed operation are significant advantages.... Ball-jointed universals are used for high-speed operation and for carrying large torques. They are available in miniature and standard sizes.
SDP/SI pioneered the concept of combining the exceptional qualities of selected plastic materials with different metals to create products which incorporate both. “SUPER-PLAST®” designs have the following advantages:
• Inexpensive replacement of metal components
• Dampens vibration
• Corrosive and chemical resistant
• Electrically insulated
SDP/SI offers an extensive selection of inch and metric dimensioned universal joints available in steel, stainless steel, acetal and acetal with brass spider and inserts as standard catalog items.
The molded universal joints can be manufactured to special requirements:
• Bores molded to accommodate square, “D” shape or hexagonal shafts
• Shafts molded into the components
• Zero backlash or components with built-in backlash
• Gears, pulleys or other components molded or assembled to couplings or universal joints
Call to discuss your special need or application.
NEW FLEXIBLE DISK-TYPE COUPLINGS:
AVAILABLE IN:
Materials: Stainless Steel, Aluminum
Bore Size: 3mm - 12mm
Outer Diameter: 15mm - 39mm
Length: 16.5mm - 32.8mm
Stock Drive Products/Sterling Instrument (SDP/SI) expands their selection of flexible couplings to include the single disk type couplings (short type), series S50XHSM… and the double disk type couplings (standard length type), series
These disk-type flexible couplings are an economical option while providing greater torque capability and improved performance in a reduced size. The compact design provides torque ratings of 0.6 up to 12 Nm, an improvement over similar products. Device manufacturers can benefit from the smaller size and reduced weight while gaining greater torque capacity and power. As a high-performance motion control coupling, disk-type couplings are well suited for applications where precise position accuracy is required.
Stock Drive Products/Sterling Instrument (SDP/SI) expands their selection of flexible couplings to include the single disk type couplings (short type), seriesand the double disk type couplings (standard length type), series S50XHWM ..These disk-type flexible couplings are an economical option while providing greater torque capability and improved performance in a reduced size. The compact design provides torque ratings of 0.6 up to 12 Nm, an improvement over similar products. Device manufacturers can benefit from the smaller size and reduced weight while gaining greater torque capacity and power. As a high-performance motion control coupling, disk-type couplings are well suited for applications where precise position accuracy is required.
PRECISION FLEXIBLE BELLOWS COUPLINGS:
AVAILABLE IN:
Materials: Brass, Bronze, Stainless Steel, Nickel, Steel, Aluminum, Neoprene, Nylon, Zinc
Bore Size: 0. in. (1mm) - 1.750 in. (45mm)
Outer Diameter: 0.250 in. (6.4mm) - 3.700 in. (94mm)
Length: 0.480 in. (14.2mm) - 3.55 in. (90.3mm)
SDP/SI Bellows Couplings are flexible couplings designed to accommodate various types of load conditions. SDP/SI Hi-Flex Bellows Couplings are used for applications which require large amounts of shaft misalignment combined with low resultant radial loads on the bearings. SDP/SI Modular Bellows Couplings are configurable and provide high torsional rigidity for high speed torque transmission. A wide variety of bore sizes and combinations are offered to accommodate specific needs.
SDP/SI Bellows Couplings are flexible couplings designed to accommodate various types of load conditions. SDP/SI Hi-Flex Bellows Couplings are used for applications which require large amounts of shaft misalignment combined with low resultant radial loads on the bearings. SDP/SI Modular Bellows Couplings are configurable and provide high torsional rigidity for high speed torque transmission. A wide variety of bore sizes and combinations are offered to accommodate specific needs.
PRECISION FLEXIBLE HELICAL COUPLINGS:
AVAILABLE IN:
Materials: Aluminum, Stainless Steel, Steel
Bore Size: 0.094 in. (2mm) - 1.00 in. (12mm)
Outer Diameter: 1/4 in. (6.35mm) - 2 1/4 in. (31.8mm)
Length: 0.37 in. (20mm) - 3.50 in. (58mm)
SDP/SI Helical Couplings, or beam couplings, are another type of flexible coupling allowing for axial motion, angular misalignment and parallel offset. This coupling design features one-piece construction resulting in zero backlash. The coupling is made flexible by removing material from the piece in a spiral pattern. SDP/SI Helical Couplings are available in aluminum and stainless steel.
SDP/SI Helical Couplings, or beam couplings, are another type of flexible coupling allowing for axial motion, angular misalignment and parallel offset. This coupling design features one-piece construction resulting in zero backlash. The coupling is made flexible by removing material from the piece in a spiral pattern. SDP/SI Helical Couplings are available in aluminum and stainless steel.
COMMERCIAL & PRECISION FLEXIBLE COUPLINGS:
AVAILABLE IN:
Materials (include): Aluminum, Stainless, Steel, Resin, Brass, Bronze, Steel, Iron, Nickel, Copper, Polymer, Rubber, Acetal, Neoprene, Nylon, Zinc, Silicone, Polyurethane, Polyimide, Polyethylene, Fiberglass
Bore: 0. in. (1mm) - 1.750 in. (45mm)
Outer Diameter: 0.25 in. (6.4mm) - 3.70 in. (94mm)
Length: 0.375 in. (7mm) - 3.55 in. (90.3mm)
Flexible Couplings have the ability to compensate for shaft misalignment and are designed to accommodate various types of load conditions. No one type of coupling can provide the universal solution to all coupling problems; hence many designs are available, each possessing construction features to accommodate one or more types of application requirements. SDP/SI offers many styles of flexible couplings, such as bellows couplings, helical couplings, oldham couplings, universal joints, and flexible shafts.
Flexible Couplings have the ability to compensate for shaft misalignment and are designed to accommodate various types of load conditions. No one type of coupling can provide the universal solution to all coupling problems; hence many designs are available, each possessing construction features to accommodate one or more types of application requirements. SDP/SI offers many styles of flexible couplings, such as bellows couplings, helical couplings, oldham couplings, universal joints, and flexible shafts.
PRECISION FLEXIBLE ANTIVIBRATION COUPLINGS:
AVAILABLE IN:
Materials: Aluminum, Steel, Rubber
Bore Size: 3 mm - 16 mm
Outer Diameter: 15 mm - 39 mm
Length: 18 mm - 55 mm
For position accuracy and vibration reduction in a servo system, these couplings solve misalignment challenges in response-mandatory servo systems designed for the semiconductor manufacturing equipment industry, scanning equipment and many automation applications. Standard sizes available in. bores 3 mm thru 16 mm. Call for custom requirements.
For position accuracy and vibration reduction in a servo system, these couplings solve misalignment challenges in response-mandatory servo systems designed for the semiconductor manufacturing equipment industry, scanning equipment and many automation applications. Standard sizes available in. bores 3 mm thru 16 mm.
PRECISION FLEXIBLE JUNIOR (BOWEX NYLON) COUPLINGS:
AVAILABLE IN:
Materials: Nylon
Bore Size: 6 mm - 20 mm
Outer Diameter: 40 mm - 52 mm
Length: 48 mm - 56 mm
Two-and Three-Piece Junior Couplings are curved tooth gear couplings made of nylon. Designed to compensate for axial, radial and angular misalignment, they are lightweight and maintenance free.
Two-and Three-Piece Junior Couplings are curved tooth gear couplings made of nylon. Designed to compensate for axial, radial and angular misalignment, they are lightweight and maintenance free.
PRECISION MAGNETIC DISK COUPLINGS:
For more information, please visit Zhenjing.
AVAILABLE IN:
Materials: Stainless Steel, Steel, Nickel
Bore Size: 0.125 in. (5mm) - 1.000 in. (19mm)
Outer Diameter: 1.06 in. (27mm) - 2.86 in. (73mm)
Length: 0.63 in. (15mm) - 1.00 in. (25.4mm)
A magnetic coupling transfers torque by using a magnetic field rather than a physical mechanized connection to transfer torque from an input shaft to the output shaft.
Because a non-contact magnetic bond is established between the two shafts, these couplings are most commonly utilized for liquid pumps and propeller systems where seals will wear out or break over time as the two surfaces slide against each other. Magnetic couplings use extremely strong natural magnets to transfer torque (without physically touching).
A magnetic coupling transfers torque by using a magnetic field rather than a physical mechanized connection to transfer torque from an input shaft to the output shaft.Because a non-contact magnetic bond is established between the two shafts, these couplings are most commonly utilized for liquid pumps and propeller systems where seals will wear out or break over time as the two surfaces slide against each other. Magnetic couplings use extremely strong natural magnets to transfer torque (without physically touching).
PRECISION MINIATURE BALL COUPLINGS:
PRECISION MULTI - JAWED COUPLINGS:
AVAILABLE IN:
Materials: Stainless Steel
Bore Size: 0. in. - 0. in.
Outer Diameter: 0.75 in.
Length: 0.87 in.
SDP/SI Precision Multi-jawed Coupling is a rigid coupling that accommodates minimal shaft misalignment. The helical gear coupling enables a positive connection between two shafts that can be disconnected or connected at any time when stopped.
SDP/SI Precision Multi-jawed Coupling is a rigid coupling that accommodates minimal shaft misalignment. The helical gear coupling enables a positive connection between two shafts that can be disconnected or connected at any time when stopped.
COMMERCIAL & PRECISION OLDHAM COUPLINGS:
AVAILABLE IN:
Materials: Stainless Steel, Aluminum, Acetal, Brass
Bore Size: 0.125 in. (2mm) - . in. (12mm)
Outer Diameter: 0.25 in. (6.4mm) - 1.62 in. (41.1mm)
Length: 0.50 in. (12.7mm) - 2.00 in. (50.8mm)
An Oldham coupling consists of three parts: one hub that is connected to the input shaft, one hub that is connected to the output shaft, and a floating member that is connected to the first two by tongue and groove in the center of the coupling. One side's tongue and groove is 90° or perpendicular to the other's tongue and groove. The input and output shafts rotate at the same speed as the middle member, around its center. Twice per rotation, the center traces a circular orbit around the halfway of the input and output shafts. To prevent backlash, springs are typically employed.
Oldham Couplings can accommodate lateral shaft misalignments up to 10% of nominal shaft diameters and up to 3° angular misalignments. Lubrication can be a problem but in most applications, can be overcome by choosing a coupling that uses a wear resistant plastic or an elastomer member in place of steel or bronze floating members.
An Oldham coupling consists of three parts: one hub that is connected to the input shaft, one hub that is connected to the output shaft, and a floating member that is connected to the first two by tongue and groove in the center of the coupling. One side's tongue and groove is 90° or perpendicular to the other's tongue and groove. The input and output shafts rotate at the same speed as the middle member, around its center. Twice per rotation, the center traces a circular orbit around the halfway of the input and output shafts. To prevent backlash, springs are typically employed.Oldham Couplings can accommodate lateral shaft misalignments up to 10% of nominal shaft diameters and up to 3° angular misalignments. Lubrication can be a problem but in most applications, can be overcome by choosing a coupling that uses a wear resistant plastic or an elastomer member in place of steel or bronze floating members.
COMMERCIAL & PRECISION RIGID SHAFT COUPLINGS:
AVAILABLE IN:
Materials: Stainless Steel, Acetal, Aluminum, Steel, Brass
Bore Size: 0.09 in. (0.8mm) - 0.50 in. (15.0mm)
Outer Diameter: 0.125 in. (7mm) - 0.53 in. (27mm)
Length: 0.21 in. (7mm) - 1.00 in. (38mm)
Rigid Couplings have limited applications unlike flexible couplings. Rigid couplings do not have the ability to compensate for shaft misalignments are therefore used where shafts are already positioned in precise lateral and angular alignment. Because of their simple rugged design, rigid couplings are generally able to transmit more power than flexible couplings of comparable size. However, this is not an important advantage, unless the application is high horsepower.
Rigid Couplings have limited applications unlike flexible couplings. Rigid couplings do not have the ability to compensate for shaft misalignments are therefore used where shafts are already positioned in precise lateral and angular alignment. Because of their simple rugged design, rigid couplings are generally able to transmit more power than flexible couplings of comparable size. However, this is not an important advantage, unless the application is high horsepower.
COMMERCIAL FLEXIBLE SHAFTS WITH CASING:
AVAILABLE IN:
Materials: Bronze, Brass, Steel
Flexible Shaft Diameter: 0.13 in. - 0.25 in.
Length: 24 in. - 48 in.
PRECISION & COMMERCIAL FLEXIBLE SHAFTS WITHOUT CASING:
PRECISION & COMMERCIAL METAL UNIVERSAL JOINTS:
AVAILABLE IN:
Materials: Stainless, Steel, Steel, Zinc
Bore Size: 0. in. (2.5mm) - 0. in. (20mm)
Outer Diameter: 3/16 in. (4.76mm) - 1 in. (32mm)
Length: 1 in. (25.4mm) - 7.30 in. (185mm)
Single and double joint stainless steel and alloy steel universal joints are offered with a variety of bore sizes. Miniature universal joints feature zero backlash, sealed-in lubrication and low inertia. Inverted design universal joints are small in size and lightweight for given torque capacity. These joints may be made into telescoping units by mating them with telescoping miniature ball splines.
Single and double joint stainless steel and alloy steel universal joints are offered with a variety of bore sizes. Miniature universal joints feature zero backlash, sealed-in lubrication and low inertia. Inverted design universal joints are small in size and lightweight for given torque capacity. These joints may be made into telescoping units by mating them with telescoping miniature ball splines.
COMMERCIAL PLASTIC UNIVERSAL JOINTS:
AVAILABLE IN:
Materials: Acetal
Bore Size: 1/8 in. (2mm) - 3/8 in. (10mm)
Outer Diameter: 1/4 in. (6.3mm) - 5/8 in. (15.9mm)
Length: 3/4 in. (19mm) - 4 13/32 in. (111.8mm)
Plastic universal joints are inexpensive, dampen vibration, electrically insulating, and are well suited for low torque applications. We offer a wide variety of sizes and styles as standard catalog items. We can also manufacture them to specific requirements, please consult SDP/SI Engineering for further details.
Plastic universal joints are inexpensive, dampen vibration, electrically insulating, and are well suited for low torque applications. We offer a wide variety of sizes and styles as standard catalog items. We can also manufacture them to specific requirements, please consult SDP/SI Engineering for further details.
COMMERCIAL TELESCOPING UNIVERSAL JOINTS:
AVAILABLE IN:
Materials: Acetal, Brass, Stainless Steel
Bore Size: 0.125 in. (2mm) - 0. in. (14mm)
Outer Diameter: 0.25 in. (6.3mm) - 0.625 in. (25.41mm)
Length(closed): 1.5 in. (38.1mm) - 10.1 in. (256mm)
Stainless steel telescoping universal joints are offered in a number of sizes and are heat and corrosion resistant. Telescoping miniature universal joints feature zero backlash and accommodate 1/4 axial motion. Molded universal joints with a molded slide extension or brass slide extension are available in a variety of sizes, shorter or longer lengths are available on special order.
Stainless steel telescoping universal joints are offered in a number of sizes and are heat and corrosion resistant. Telescoping miniature universal joints feature zero backlash and accommodate 1/4 axial motion. Molded universal joints with a molded slide extension or brass slide extension are available in a variety of sizes, shorter or longer lengths are available on special order.
PRECISION ZERO BACKLASH UNIVERSAL JOINTS:
Grooved pipe couplings are some of the most important equipment in fire protection, allowing quick and water-tight connections without pipe threads, flanges, or welding. Instead, installers simply butt the ends of pipes together and seal them with a gasket and clamp.
But there are also two kinds of grooved couplings that serve different purposes. Rigid grooved couplings don’t allow much movement and serve as a standard pipe joint. But for situations where some give is needed—specifically, seismic protection of fire sprinkler systems—flexible grooved couplings are the solution.
This article reviews the basics of grooved pipe couplings and details the differences between a rigid and flexible coupling. We also explain when and how NFPA 13: Standard for the Installation of Fire Sprinkler Systems ( edition) requires using flexible couplings for seismic protection.
Shop our selection of rigid grooved couplings and other fittings for your pipe-joining needs. Looking for flexible couplings? Contact QRFS today for a quote or to place a special order.
Grooved couplings are the fastest way to join pipes. And the technology is simple. Earnest Tribe, the founder of Victaulic, patented the grooved pipe joint in after developing the tech to meet wartime needs. Grooved couplings avoid the need for welding or other joint types. Instead, they use three components: 1) pipe with grooved ends, 2) synthetic rubber gaskets, and 3) c-shaped clamps.
To form a joint, installers butt two pipes with grooves cut in the ends together. A lubricated gasket slips over the pipe ends so that it overlaps the joint. And a c-shaped clamp or housing fits into the grooves of the pipe, compressing and stabilizing the gasket. This video from Victaulic shows how the joints are made:
But as we mentioned, there are two kinds of grooved joints. So, what’s the difference between a rigid and flexible coupling?
From the outside, you can’t look at a grooved coupling and know whether it’s rigid or flexible; they look the same. The difference is on the inside of the joint in the way that the gasket, groove, and clamp fit together. A rigid clamp permits next to no separation, rotation, or angular movement. But a flexible coupling permits some movement and space without compromising the seal or damaging the pipe. NFPA 13 officially describes how much flexibility is allowed:
3.3.83 Flexible Coupling. A listed coupling or fitting that allows axial displacement, rotation, and at least 1 degree of angular movement of the pipe without inducing harm on the pipe. For pipe diameters of 8 in. (200 mm) and larger, the angular movement is permitted to be less than 1 degree but not less than 0.5 degree.
Key to this definition is the term “listed.” A testing laboratory such as UL or FM Global must verify that a flexible grooved fitting meets specific flexibility, seal, and strength requirements before it can be used in a fire sprinkler system.
This diagram from Bentley Communities helps illustrate the physical difference between the two types of joints:
Almost all grooved couplings use rigid joints because rigid, unmoving joints are desired for most situations. But flexible couplings, while less common, do play essential roles in seismic protection for fire sprinkler systems that require an earthquake-resistant design.
Some fire sprinkler systems require design measures to protect them from earthquake damage. In our overview of the principles of seismic protection, we explain the two basic techniques for protecting pipes from damage: adding rigidity and adding flexibility. Rigidity, in the form of seismic bracing, ensures that pipe moves with a building in an earthquake instead of shaking violently and breaking loose.
Flexibility, on the other hand, prevents damage to pipes caused by differential movement. When an earthquake’s powerful p-waves shake a building, the whole structure can move—but not always all at the same time. For example, the ground floor moves first in tall buildings, and the top floors lag behind. This wave-like motion that resembles a slinky is called “story displacement.” And the differential movement it causes in various onsite equipment can snap fire sprinkler pipes.
The solution to this problem is flexibility, which designers can achieve with flexible grooved couplings. The modest ‘give’ allowed by these devices can prevent pipes from being damaged in an earthquake.
NFPA 13 requires grooved flexible couplings for pipes that are 2 ½” or larger (Section 18.2.1) in certain buildings that fall into specific design categories (SDC). And because story displacement significantly affects risers, most of these rules involve risers (18.2.3.1):
Flexible couplings are also required at horizontal tie-ins to the riser (18.2.3.2) and the connection of drop-pipes (18.2.4).
Flexible couplings allow flexibility when two structures move independently. But don’t forget that bracing, which ensures pipe moves with a building, is the other core technique of seismic design. Flexible couplings can work against this objective by reducing rigidity. So, to compensate, NFPA 13 says that flexible couplings should only coincide with structural separations (18.2.2). And where they are used outside the explicit instructions, extra sway braces are needed (18.2.3).
In our previous blogs, you can learn more about the principles of sway bracing and how cable sway braces work.
Flexible couplings can also be used to construct seismic separation assemblies. These pipe assemblies are used where horizontal pipe must cross an engineered gap, called a seismic joint, between two structures.
The “structures” can be two independent buildings or two freestanding wings of the same building. When a pipe crosses a gap like this, NFPA 13 requires seismic separation assemblies (18.3.1) to keep it from breaking when the two structures move during an earthquake.
There are two ways to build a seismic separation assembly (18.3.2). One approach uses flexible pipe arranged in a u-bend. The other involves a zig-zag pattern of flexible grooved elbows. Either way, the assembly should accommodate a wide range of motion in three directions: the complete closing of the gap between the structures, a doubling of the gap, or lateral movement equal to the size of the gap.
You need a stiff joint for the vast majority of sprinkler pipe connections. That’s why most grooved pipe joints use rigid couplings. But sometimes, flexibility is necessary for seismic design, and the extra range of motion provided by flexible couplings can prevent earthquake damage.
Be sure to check your local codes, including whether a building falls within a seismic design category (SDC) that requires special equipment to keep fire protection systems safe. A qualified system designer must make this determination. Regardless of what you need, QRFS can provide:
If you have questions or need help finding the part you need, call us at (888) 361- or .
If you want to learn more, please visit our website Flange Rigid Coupling.