Pipe rolls
Pipe rolls for pipelines are planned and realized to carry either pipes dead weight and the one of fluids running in them but above all to make a free sliding of pipelines easy, due to thermical range.
Pipe stands are able to highly reduce attritions thanks to stainless steel pin and to the sintered bushings on which a roll is set up.
Since sliding rolls are able to maintain their sliding role unaltered for a long time no maintenance is necessary.
In pipelines with large diameter but small thickness in order to avoid buckling due to peak loads gathered together in one point, we suggest you to place saddles "SELLA" at small distances.
Axial expansion joints
Because of strengths generated by inside pressure, axial expansion joints have been planned to lengthen and to buckle sidewards.
Slides must therefore assure an extreme axial freely movement to pipeline and at the same time must prevent any traverse and upwards movement since owing to the presence of the peak load pipeline even might rise in consequence of an eventual slight starting eccentricity too. Therefore, swing and catenary suspensions must be strictly avoided and strictly avoided when they have no lateral restraints too.
To eliminate risk of not alignment it's fundamental to foresee in every rectilinear section already setted, anchor points strong enough and some restraining guide towards all lateral directions, placed in suitable space as per instructions listed on the following table.
Angular and gimbal joints
Flexible joints, contrary to the axial ones, produce moderate thrusts against anchor points. In case of short pipe connections among central plant equipments, slides seem to be even useless. The dead weight of connecting pipe sections between joints has to be supported in order not to hinder movements.
In case of long pipelines, axial slides are to be installed before the first joint and after the last one. Such slides must facilitate free pipeline expansion.
The distance between slide and the first joint of pipe network must not be longer than two times nominal diameter plus half movement.
In these pipe systems the weight of connecting pipe sections between the joints has to be neutralized by simple roller sliding stands (see supports).
In vertical systems the weight of connecting pipe sections can be neutralized, if it's necessary, through counterweights or spring suspensions which let the joints free to expand and shrink.
Universal joints
Strong slides are not strictly necessary provided that:

1st) a suitable side clearance in the last section of pipe just near flexible joints be planned for slides. As a matter of fact said clearance will enable slides to absorb the value of stresses in connection with the arch height;

2nd) frictional forces generated by slides be of no account.
A good sliding of slides is necessary to ensure regular and constant movement to pipeline in order to avoid dangerous expansion stoppings.
As above must be carefully arranged in advance otherwise pipeline after having overcome the obstacles that obstructed its normal expansion, would suddenly expand in a violent way with thrusts and dangerous shakings.
Pipe rolls
DN 40 50 65 80 100 125 150 200 250 300 350 400 450 500 600 700
L1=4Ø 0.15 0.2 0.25 0.3 0.4 0.5 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.4 2.8
L2=14Ø 0.56 0.7 0.9 1.1 1.4 1.75 2.1 2.8 3.5 4.2 4.9 5.6 6.3 7 8.4 9.8
L3 2 2.5 3 3.5 4 4.5 5 6 6.3 7 7.5 8 8.5 9 10 10.5
Technical data