National fittings has been a manufacturer of components for grooved piping system with innovative design, economical production practices, acceptable quality controls and service oriented marketing to the international markets. ‘National’ brand grooved products are well accepted in most countries.
National Grooved piping system is reliable and is faster to install than welding, threading or flanging, resulting in lowest installed cost. It can be adopted to suit standard pipe with cut grooves or standard and light wall pipe with rolled grooves. Triple sealing of the C-shaped pressure responsive gasket is made from specially compounded rubbers with low compression set property. Couplings perform equally well under pressure and vacuum. Couplings with Tri-seal gaskets are highly suitable for higher vacuum service and dry systems subject to freezing. Couplings are available for flexible and rigid system. Grooved end fitting are machined to AWWA c606 cut groove standard Products are offered with RAL 3000 alkyl enamel rust preventive paint as standard and hot dipped galvanized coating is available optionally.
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Ductile Iron
National is a growing force in the International field of Ductile Iron grooved fittings. National fittings are used for fire fighting and HVAC lines in USA, Canada, Western Europe, Australia, Japan and Asia.
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Stainless Steel
National also manufactures grooved fittings in stainless steel using investment casting or lost wax process. National stainless steel grooved fittings are used in a variety of applications across industries.
Product Features
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Reduced Costs
Coupling assembly is quick and easy. Special training not required. The system is free from contaminates such as weld slag and pipe dope. Installation costs are controllable and estimates are more precise.
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Union Type Joint
Couplings can be disassembled easily permitting maintenance and servicing of the piping system. It will facilitate periodic rotation of pipe to distribute internal wear from slurries or other abrasive media.
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Reliability
The couplings engage the pipe around the entire circumference and restrain the pipe ends from separation due to pressure and other forces, up to the maximum coupling rated working pressure.
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Deflection & Misalignment Allowance
Precise location of pipe openings through walls and floors is unnecessary. Long radius curves may be designed with fewer elbows. useful for providing pitch for drainage Facilitiates laying pipe on rough or uneven terrain.
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Expansion & Contraction Allowance
Provides linear movement at each joint. Allows pipe expansion and contraction. Suitable for hot and cold water lines and dual temperature systems.
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Stress-Free Joint
Flexibility of the joint reduces or eliminates stresses from settlement of burried pipe or induced by seismic tremors.
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Noise & Vibration Isolation
Slight gap between pipe ends isolates noise and ibration. Resilient gasket also helps to absorb noise and vibration. Often permits elimination of noise suppression devices.
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Rigidity
Couplings available for rigidity at valves, equipment or mechanical rooms. Couplings grip pipe to provide a rigid system used with standard groove specifications