Spiral hose

Blends based on nitrile rubbers are used in underground wire/cable covering automotive weatherstripping, spoiler extensions, foam-integral skin core-cover armrests, and window frames footwear and flexible, lay-flat, reinforced, rigid, and spiral hose for oils, water, food, and compressed air. 

The rubber hose industry is one of the two largest segments of nontire rubber fabricators. Worldwide, the hose industry had about 6 billion dollars in total sales in 2010. Automotive and industrial are two very large market areas for hose. Some hose processes, for machine-made and hand-built hose, are very labor intensive. Processes for braided and spiral hose are less labor intensive. Hoses constructed in the factory are commonly cured in autoclaves. 

Vibration is both a cause of problems and an effect of equipment problems. The potential destructive force of an out-of-balance load has led to setting lower shutdown limits on the magnitude of vibration than other rotating equipment. Flexible connections for process and utility lines become a must so these vibration problems are not transmitted to connected equipment. Flexible hoses with liners having concentric convolutions (bellows type) avoid the sharp points inherent with spiral metallic liners. By avoiding the sharp point the liner is less likely to cut the exterior covering. 

In reality the charging current increases in the smaller diameter dip pipe. Also, small diameter spiral-wound hose can in some cases greatly increase charging current. This effect is presumed due to increased turbulence at the inner wall [8]. Eor overhead filling of road and rail tankers the maximum vd products recommended in this book are respectively 0.38 mVs and 0.50 mVs, which are smaller than the maximum recommended values given in... 

Flexible hose must not be twisted during installation. This will reduce the life of the hose and may cause the fittings to loosen. You can determine whether a hose is twisted by looking at the layline that runs along the length of the hose. If the layline does not spiral around the hose, the hose is not twisted. If the layline does spiral around the hose, the hose is twisted and must be untwisted. Flexible... 

These fabrics can be applied in the hand-built construction of hoses in a spiral form at an angle to the axis of the hose. The knitted fabric can also be produced directly onto the surface of the inner liner of a hose and subsequently be covered with the outer cover compound by a cross-head extruder. 

Hose may be hand built using a three roll wrapping machine. The centres of the three rolls form an equilateral triangle. The hose during construction sits on the junction between the two lower rollers and pressure is exerted to consolidate the composite by the upper movable roller. An extruded inner liner, after fitting to a solid inner mandrel, is placed into the machine between the rollers and then the various layers of rubber coated or resorcinol-formaldehyde-latex treated, fabric are applied in a spiral form, with overlap. Once the reinforcement layers have been added the cover rubber is applied and a cloth, usually nylon, is spirally wrapped around the constructed hose using the roller system. The hose is now ready for vulcanisation. 

On August 14, 2002, a 1-in chlorine transfer hose (CTH) used in a rail-car offloading operation at DPC Enterprises in Festus, Missouri, catastrophically ruptured and initiated a sequence of events that led to the release of 48,000 lb of chlorine into neighboring areas. The material of construction of the ruptured hose was incorrect. The distributor fabricated bulk CTH with Schedule 80 Monel 400 end fittings and a high-density polyethylene spiral guard. Three hoses were shipped directly to the Festus facility from the distributor two were put into service on June 15, 2002. The hose involved in the incident failed after 59 days in service. 

Some applications require flexibility to bend and curl the hoses. To accomplish this, the extmded and sintered tubes can be convoluted in a separate step. The tube is passed through a heated die, which melts the PTFE and creates a spiral peak and valley pattern into the tube. A key requirement of the convolution process is to assure that the wall thickness remains uniform, in other words, the tube is not stretched. Any thinning of the wall will weaken and reduce the burst pressure of the hose. Figure 5.31c shows an example of convoluted tube, which is partly braided with stainless steel. 

The extrusion head [94] shown in Fig. 2.21 contains a unit for preparation of the inhibiting mixture that is made as a vortical tube. The polymer melt is fed from extruder 7 into annular slot 6 formed by mandrel 9 and nozzle 5, and is squeezed as a hose 3. The compressed air is fed into nozzle 10 of scroll 11, and into nozzle 15, and Cl is fed from tank 14 in a liquid or gaseous state. The compressed air and Cl are accelerated in the scroll over the spiral and form a swirl flow of a homogeneous mixture in duct 8. The peripheral layers of the flow become heated and the Cl (if it is a liquid) evaporates, whereas... 

The arrangement of the spots on the film surface depends on the spraying regime and bush 12 travel pattern. Reciprocation of the bush creates vertical stripes, its rotary motion results in spiral curls (combining radial shifts of the Cl jets with the vertical travel of the film). Pulse spraying at variable velocity of bush 12 produces intricate drawings on the hose surface. 

Foi e Loop, Spiral wound corrugated hose. Action Technology Co. 

Newfiex, Spiral reinforced PVC hose. New Age Industries Inc., Plastics Technology Group... 

Spiralock, Vacuum hose and ducting, Plastiflex Spiratube, Spirally cut tubing, Hudson Extrusions, Inc. 

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