Metal Flexible Hose
ENETAF SANE metal flexible hoses are kinds of flexible joints made of stainless steel which are applied with the purpose of eliminating vibrations generally on non-planar piping paths.Furthermore, they are useable in misaligned piping. They have upper most level of flexibility and pressure , internal corrosion and external abrasion resistance . Flexible hoses are made of a bellows as well as one or more layers of braids. The metal flexible hose can be welded , flange type , male threaded and union nut type
Covering a range of working temperature from -200 to 800 °C .
Having a small bending radius , as a matter of flexibility .
Bellows are made of different stainless steels same as : 321 , 316 , 316L , 304 & 304L .
Sizes from 14 to 600 mm diameter .
Besides reinforcing bellows against pressure , braid is a protecting cover against mechanical damages or fire .
Metal flexible hoses are being applied for special purposes like damping vibrations , vacuum situation , high temperatures , sound pollution neutralization , fluid directing in reciprocal and bending pipe paths , effective performance in high pressure situation , correction of pipeline misalignments and etc
Flexible hoses are vastly used as flexible joints in suction or discharge side of pumps. They prevent vibrational and due to extension / contraction damages . They absorb thermal expansions as well as slight due to misalignment stresses. The woven braid covering the bellows is a perfectly suitable structure which enables flexible hoses to tolerate large movements accompanied by high pressures
In situations similar to earthquake in which in addition to thermal expansions / contractions , accessories might be under accidental loads , there shall exist an ability of multidirectional movement absorption and U-type flexible hoses are kinds of best options in such situations U-type flexible hoses allow boilers , chillers , fan coils and other similar systems to move freely in relation to the rest of the structure. U-type flexible hoses are also being used in order to prevent nozzles from cracking or being cut. Flexible hoses are totally applied in different industries like steel , cement , food , petroleum , gas , petrochemical and etc
Design of corrugations
Flexible hoses are made of a thin stainless steel band formed as a tube , seamed by longitudinal welding and finally corrugated with convoluted profiles . It means that each corrugation is perpendicular to the pipe centerline and its movement is independent from other corrugations . We call them “low pitch” when corrugations are positioned too close to each other and “high pitch” when they are a little bit farther from each other
For situations in which we need more bending flexibility, hoses with Ω shaped corrugations are applied that for the sake of increasing number of convolutions per unit length without thickness reduction of the bellows plate, they benefit from a longer lifetime in bend loadings. This type of flexible hose tends to return to its initial form when released from loading and also they are appropriate for vacuum situation. Ω shaped corrugations are more pressure resistant as well
Flexibility of a metal flexible hose is result of its convolutions bending. A flexible hose life time depends on its bending stiffness, working temperature, corrosive condition, pressure and applied vibrations. Braid doesn’t affect hose flexibility so much, but a flexible hose which is exposed to excessive tension, might over elongate and consequently the corrugations might get opened up. For higher pressures two braid layers are applied and for vacuum or extremely low pressure situations a corrugated hose without any braid might be used