Elaflex BlackBand ERV-CR Rubber Bellows
The Elaflex BlackBand ERV-CR rubber bellow features a Chloroprene CR, seamless, abrasion resistant liner with PA textile cord reinforcement and Chloroprene CR cover. Suitable for cold and warm water, swimming pool water, sea water, waste water (weakly sour or alkaline), water containing oil, cooling water with oily additives, lubricating oil, grease and air and compressed air. The BlackBand ERV-CR is available from DN25 to DN1000 with a wide choice of configuration, flange and restraint options:
Untied(no restraints)
TiedOuter
TiedOuter & Inner
TiedAngular Restraint
Elaflex Rubber Bellows
What is an Elaflex ERV-CR Rubber Bellows?
Versatile choice for water, weak chemicals, oils...
- Materials
Chloroprene CR, swivel flanges as standard in zinc plated carbon steel - Application
Water services including contaminated / oily, oils, greases, compressed air, not suitable for drinking water - Rating
PN16 to DN400, PN10 to DN1000 -40°C up to +90°C, temporarily up to +100°C. Electrically non conductive. - Approvals
DNV / BV / CCS
How to select an Elaflex rubber bellows
Temperature is the most critical as it directly influences the choice of rubber - but also the actual pressure capability of the bellows. The stated maximum rated pressure is maintained up to around 50ºC for most rubber bellows, for higher temperatures check the data in the Range tab.
The rubber compound used for the inner layer of the bellows must be compatible with the working fluid. Drinking water requires a WRAS approved EPDM, oils require Nitrile and so on - our Bellows Finder can help you with finding the right rubber.
Moulded bellows are manufactured in set combinations of diameters and lengths. However, our handmade Safetech range can be manufactured in any diameter and length to suit your application, only the more standard sizes are shown on the Safetech range tab.
Any flange drilling can be supplied; if you are uncertain about what you already have installed our Flange Finder will help you identify it. The HVAC and Elaflex ranges have swivel flanges; the Safetech range has full face rubber flanges. Our web shop stock is PN10/16. Bellows will exert a pressure force on the pipe (see FAQ) which must be restrained or absorbed at the piping anchors. All our flanged rubber expansion joints are available with tie rods and we can offer hinges or gimbals on the Elaflex and Safetech products.
Moulded rubber bellows have a defined movement range, which is shown for each type in the Range tab, movements listed are non-concurrent (see FAQ). A Safetech bellows will be designed to meet your required movements.
Call our expert team on +44 (0) 1384 881188 or email us at sales@flexej.co.uk or use Live Chat on this web site - we are here to help, please get in touch.
BlackBand ERV-CR standard restraint options:
FlexEJ has tie rod restraint options in stock for the BlackBand ERV-CR bellows range. Angular and other configurations can be engineered to your exact requirements, however complex:
Without Restraints
(Untied)
WITHOUT RESTRAINTS
No movement restriction, pressure force acts on pipe
The bellows will exert a pressure force on the pipe (see FAQ) as the bellows tries to elongate which must be absorbed at the piping anchors. Any equipment connected to the bellows must have an adequate flange load rating.
Tie rods with outer nuts
(Tied)
TIE RODS WITH OUTER NUTS
No axial extension, pressure force restrained
Tie rods with outer nuts only restrict the elongation of the bellows under pressure and restrains the pressure force. Up to DN300 the tie bars lie elastically in noise-reducing rubber bushes of weatherproof rubber, from DN350 steel spherical washers are provided. The bellows can move laterally. Axial compression is also possible but only if the piping overcomes the pressure force.
Tie rods with inner and outer nuts
(Lateral only)
TIE RODS WITH INNER AND OUTER NUTS
No axial extension or compression, pressure force restrained
Tie rods with inner and outer nuts both restrict the elongation of the bellows under pressure (restrains the pressure force) and limits axial compression. Up to DN300 the tie bars lie elastically in noise-reducing rubber bushes of weatherproof rubber, from DN350 steel spherical washers are provided. The bellows can move laterally. Axial compression is also possible but only if the piping overcomes the pressure force and a gap is set between the inner nuts and the flange.
Hinges
(Angular only)
HINGES
Angular movement only, pressure force restrained
The hinge restricts bellows movement to angular only. The pressure force is restrained by the hinge. No axial or lateral movement is possible. Two hinged bellows working together can form a very effective restrained lateral joint with low spring rate capable of very large movements.
BlackBand ERV-CR comparison chart
Is the BlackBand ERV-CR the best option for your application? Three potential alternatives to consider:
WRAS approved 
WRAS approved bellows
Is this bellow approved for use in all UK public mains water supplies?
Potable water Potable water
Is this bellow approved for water systems used for drinking and food preparation?
DIN 4809 compliant HT Heating Water DIN4809 compliant
Is this bellow compliant with the German DIN4809 standard of approval for warm water heating systems? (Max 100°C, 10 bar).
Oily & drainage water Oily & drainage water
Contaminated, oily, drain & waste water. Is this bellows suitable for contaminated water services that would degrade an EPDM rubber?
Rating barg/°C Pressure & temperature
What is the required pressure rating (in barg) compared to temperature rating for this bellow?
Industry experience
FLEXEJ Ltd was formed in 2002 by two professional engineers who brought together an already highly respected design capability with business and commercial skills gained in large multinational companies.
- Our focus has always been on application and design – helping our customers find the best value solution.
- We have a strong engineering and manufacturing team with experience in petrochemicals, refining, nuclear, desalination though to HVAC.
- The team is also very familiar with meeting complex requirements for documentation, in process NDT and test on projects. We have supplied many large end-users such as EDF, Exxon, Shell, Reliance & QatarGas working with major contractors such as JGC, Foster Wheeler & Technip.
