Backdrop Bends

Backdrop Chamber Bend

Typically referred to as a Backdrop Bends, this single piece assembly is fabricated to order. Backdrop bends are offered in the required DSD drawing fitting radius (r = ≥4 x DN). The drop pipe material is M90ES SDR 17 CCTV PE 100 RC pipe, there are no joints, steps or internal weld beads in the drop or bend portion, offering an exceptionally smooth internal surface. r = 4 x DN, so the fitting meets the requirements of the following DSD drawing: 

DS1020D Backdrop Manhole Type 3 

Unlike Cast Iron, PE does not corrode so the interior surface of the PE remains smooth over the life of the fitting. Therefore the use of tighter radii bends at the bottom of the drop are possible, with limited risk of blockage.  The use of alternatives bend radii may be necessary where a r => 4 x DN bend is simply too large to install in the available space.

Mill-Pro PE Backdrop bends are supplied with a factory welded integrated puddle flange in accordance with DSD Appendix 5A Clause 5.10.3.2

When PE is cast into concrete there is no adhesion between PE and cement. Due to thermal expansion of the PE during concrete curing, a small gap is created between the PE and the cured concrete after cooling. A Hydrophilic seal is fitted where the PE exits the concrete at the manhole base, this seal expands up to 600% when wet to permanently seal the PE and concrete chamber walls. This seal is designed in accordance with DSD Appendix 5A, Clause 5.10.3.3

Approval to use Backdrop bends with r = 1xDN or 2.5 D should be sort from the engineer

 

Fabricated PE100 RC SDR 17 Backdrop Manhole Bend, radius = ≥ 4x DN.

DSD Compliant, dimensions Z1 & Z2 are stated in the tables as greater the or equal to (≥), they can be fabricated longer than the stated value below to suit site requirements, but not less than. It is recommended that dimension Z1 is ordered longer than required and cut to length on site before plastering the entrance

Product code DN dn Z1 Z2 r Availability in Hong Kong
P5314.563.160 150 160 ≥ 760 ≥ 920 720 8-12 Weeks
P5314.563.225 200 225 ≥ 1068 ≥ 1243 1013 8-12 Weeks
P5314.563.250 225 250 ≥ 1185 ≥ 1365 1125 8-12 Weeks
P5314.562.280 250 280 ≥ 1190 ≥ 1381 1120 8-12 Weeks
P5314.562.355 300 355 ≥ 1510 ≥ 1735 1420 8-12 Weeks
P5314.562.400 350/375 400 ≥ 1695 ≥ 1940 1600 8-12 Weeks
P5314.562.450 400 450 ≥ 1895 ≥ 2160 1800 8-12 Weeks
P5314.562.500 450 500 ≥ 2095 ≥ 2375 2000 8-12 Weeks

Fabricated PE100 RC SDR 17 Backdrop Manhole Bend with radius r = 2.5 x DN

Dimensions Z1 & Z2 are stated in the tables as greater the or equal to (≥), they can be fabricated longer than the stated value below to suit site requirements, but not less than. It is recommended that dimension Z1 is ordered longer than required and cut to length on site before plastering the entrance

Product code DN dn Z1 Z2 r Availability in Hong Kong
P5314.561.160 150 160 ≥ 440 ≥ 600 400 8-12 Weeks
P5314.561.225 200 225 ≥ 618 ≥ 793 563 8-12 Weeks
P5314.561.250 225 250 ≥ 685 ≥ 865 625 8-12 Weeks
P5314.561.280 250 280 ≥ 770 ≥ 961 700 8-12 Weeks
P5314.561.355 300 355 ≥ 978 ≥ 1203 888 8-12 Weeks
P5314.561.400 350/375 400 ≥ 1095 ≥ 1340 1000 8-12 Weeks
P5314.561.450 400 450 ≥ 1220 ≥ 1485 1125 8-12 Weeks
P5314.561.500 450 500 ≥ 1345 ≥ 1625 1250 8-12 Weeks
P5314.561.560 500 560 ≥ 1400 ≥ 1400 1400 8-12 Weeks
P5314.561.630 525 630 ≥ 1575 ≥ 1575 1575 8-12 Weeks

Fabricated PE100 RC SDR 17 Backdrop Manhole Bend with radius r = ~ 1x DN

Dimensions Z1 & Z2 are stated in the tables as greater the or equal to (≥), they can be fabricated longer than the stated value below to suit site requirements, but not less than. It is recommended that dimension Z1 is ordered longer than required and cut to length on site before plastering the entrance

Product code DN dn Z1 Z2 r Availability in Hong Kong
P5314.560.160 150 160 ≥ 116 ≥ 276 76 8-12 Weeks
P5314.560.225 200 225 ≥ 162 ≥ 337 107 8-12 Weeks
P5314.560.250 225 250 ≥ 179 ≥ 359 119 8-12 Weeks
P5314.560.280 250 280 ≥ 203 ≥ 394 133 8-12 Weeks
P5314.560.355 300 355 ≥ 259 ≥ 484 169 8-12 Weeks
P5314.560.400 350/375 400 ≥ 285 ≥ 530 190 8-12 Weeks
P5314.560.450 400 450 ≥ 309 ≥ 574 214 8-12 Weeks
P5314.560.500 450 500 ≥ 333 ≥ 613 238 8-12 Weeks