Stainless steel braiding

A hose assembly in fluorine service failed because of forming a leak (Fig. 10.38). The hose consisted of a PTFE tube (liner) at its core which had been reinforced with a stainless steel braiding. The failure occurred in the PTFE tube below and near the lower edge of the collar, away from the joint. The failed hose handled fluorine that had been diluted by a neutral gas. A lengthy analysis was performed to determine the cause of the failure because of the safety concerns about fluorine service. 

A PTFE-lined, stainless steel braided hose was used to transport sulphur trioxide at a chemical plant. The hose was attached to an external tank system and was insulated and heated. One day the hose failed and sulphur trioxide leaked and caused serious environmental problems. The failed hose had one long axial crack that had split the hose open, which allowed the liquid to be released. The engineering assignment in this case was to examine the cause of the failure. 

South wire Glenair ArmorLite, Stainless steel braiding, and here... 

E-9 Standard for Flexible, PTFE-Lined Pigtails for Compressed Gas Service. The standard covers flexible stainless steel braided PTFE-lined pigtails used in filling and discharging compressed gas cylinders (3 pages). 

The incident occnrred at about 1400 hours on January 23. An operator was in the phosgene shed when a stainless steel-braided FI FE hose used for transferring phosgene failed catastrophically. He was sprayed across the face and chest with about 1 kg of phosgene. It was estimated he received a fatal dose within less than one-tenth of a second. He was able to call for assistance using the phone in the phosgene shed. 

There are numerous metal-based yams on the market. For example, Bekintex (2014) markets Bekinox stainless steel multi-filament yams. Glenair (2014) markets ArmorLite , a lightweight microfilament stainless steel braid. It is used as shielding in high-performance interconnect cabling. 

Shipment, Stora.ge, ndPrice. l-Methyl-2-pyrrohdinone is available in tank cars or tank trailers as well as in dmms. Shipping containers are normally of unlined steel. Rubber hose is unsuitable for handling standard steel pipe or braided steel hose is acceptable. Ordinarily 1020 carbon steel (0550) is satisfactory as a storage material. Stainless-steel 304 and 316, nickel, and aluminum are also suitable. MethylpyrroHdinone is hygroscopic and must be protected from atmospheric moisture. In September 1994, NMP was Hsted at 3.89/kg. 

Shipment and Storage. Sulfur dichloride, if kept dry, is noncorrosive at ambient temperatures, thus carbon steel and Hon can be used Hi the constmction of tanks, piping, and dmms. However, when water or humidity is present, materials resistant to hydrochloric acid must be used, eg, glass-lined pipe. Teflon, titanium, HasteUoy C, or possibly a chemically resistant, glass-reiaforced polyester. Threaded pipe joHits should be assembled with Teflon tape. Hoses should be constmcted with a Teflon inner lining with the outer tube constmcted of Neoprene or braided 316 stainless steel protected by an adequate thickness of Teflon. Sulfur dichloride should be stored away from heat and away from dHect rays of the sum. Toluene and sulfur dichloride react exothermically when catalyzed by Hon or ferric chloride. Safety precautions should be foUowed when such a mixture is present (165). 

CNG dispensing hose uses an impervious inner tube reinforced by a braided over-wrap of stainless steel wire. The inner tube can be teflon or a similar material that is not porous and will not become overly stiff in cold weather. An unusual problem that can occur with high-pressure hose is that if static electricity builds up inside the hose, it may discharge through the hose to the wire reinforcement. When this occurs, a small hole is formed in the inner tube that quickly leads to a leak through the wire reinforcement. Such incidents are rare, but they do occur, caused by the non-conducting properties of the inner tube. There have been no reported incidents of such failures in CNG dispensing hoses. 

Absorbable sutures are collagen sutures, polyglycolic acid and its lactide copolymers, and polydioxanone. Nonabsorbable sutures include silk, cotton, polyethylene, polypropylene, nylon, PET, and stainless steel. These fibers can be used as monofilaments or multifilaments (twisted or braided). Figure 2.16 shows examples of filters for medical purposes made of polyester, nylon, and metallic fibers. In summary, fibers are used in almost everything that we can see in our... 

Coke formed on solid surfaces during the pyrolyses of acetylene, ethylene, ethane, propylene, and butadiene were examined by using a scanning electron microscope. Seven types of coke have been identified braided filament, uniform diameter filament, needle or spike, ribbon, fluffy or cottonlike fibers, knobby, and amphorous. The first four types contained metal (especially iron) and were magnetic. Magnetic cokes formed sometimes on Incoloy 800, stainless steel 304, stainless steel 410, and Hastelloy X surfaces, but never on Vycor glass or aluminized Incoloy 800 surfaces. Conditions at which each type of coke was formed are discussed. 

Figure 5.31 Reinforcement of PTFE tubing (a) braiding of PTFE tubing with stainless steel, (b) hose in TEFLON 62 with double braiding for high pressure applications, (c) overbraided convoluted tubing—natural and antistatic.

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. 

Braid surfaces at the failure point and a spot away from that area were analyzed. The external and internal surfaces of the braid at the failure area were mildly discolored because of oxidization, similar to the effect of overheating a metallic object. Optical microscopy and scanning electron microscopy showed no disturbance to the weave pattern, no deformation of metal wires, and no surface defects, based on the comparison of defective and normal areas. Energy dispersive x-ray (EDX) showed similar concentrations of iron (Fe), nickel (Ni), chromium (Cr), and molybdenum (Mo) in both areas, indicating stainless steel. A small amount of silicon (Si) was detected that was attributable to environmental contamination such as dust and dirt. 

Steel-braided hose pipes with stainless steel nozzles inserts OR polyte-traflouroethylene (PTFE)-lined pipes for handling very corrosive fluids... 

Noble mebds such as platinum-iridium are also utilized in pacemaker electrodes. In addition to the noble metals, stainless steel and tantalum can also be used in sensing (nonpacing) electrodes. Stainless steel has also been used as wire braids and reinforcements in catheters, particularly in high-pressure catheters, such as those used for radiopaque dye injection. 

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