MULTI NB Inclined Flap Valves — MULTI NB Series

Protection against drainage & sewage backwater/flooding. Inclined Flap Valve (minimum 15°) designed to be installed at the end of pipelines, either on vertical walls or directly onto the end of the pipe, to prevent backflow in sewage and drainage systems. Mounting Kit included: Stainless steel mechanical anchors are provided as standard for vertical mounting.

Multiple sizes from 7.87" - 59.06"


  • Body & Flap: Glass reinforced plastic using a isophtalic polyester resin
  • Seal: EPDM rubber
  • Mounting Kit: Stainless steel mechanical anchors

MULTI NB Inclined Flap Valves MULTI NB Series


  • Integral foamed EPDM rubber gasket for direct fixing to a flange or headwall
  • Stainless steel mechanical anchors are provided as standard for vertical wall mounting
  • For flange ISO PN 10 use standard stainless steel bolts and nuts (not provided)

Reliable and Durable

High mechanical strength due to Glass Reinforced Plastic (GRP) construction. Design is verified by Finite Element Stress Analysis


Resistant up to 1 bar (10 m head) and back pressure to 1 bar (10 m head) . Integral rubber seals easily replaced if damaged.


Fast and easy installation. Most sizes can be handled by one person. Very low operating pressure (cracking head) compared with metal flap valves.

Corrosion Resistant

Highly resistant to corrosion and UV Degradation. No coating needed.


Natural rubbers provide resistance to ozone, UV and mechanical compression.

Low Maintenance

Long service life and low maintenance.


Conforms to ISO 9001 quality standards.

  1. Reliable and Durable
  2. Watertight
  3. Lightweight
  4. Corrosion Resistant
  5. Resilient
  6. Low Maintenance
  7. Quality


A-PIPE OD B-PIPE OD C-DEPTH OF SOCKET MAX JOINT DEFLECTION ANGLE WEIGHT MAX Coupling OD Range min MAX Coupling OD Range max Larger Pipe ID min Larger Pipe ID max Smaller Pipe ID min Smaller Pipe ID max Sewer Main Wall Thickness Lateral Pipe min Lateral Pipe max Core Drilling min Sewer Main Core Break min Sewer Main Core Break max Foam Qty Required DIM. A DIM B DIM C DIM D DIM E DIM F Weight Pressure Resistance Pipe O.D. 2 Bushings (TWP) Pipe O.D. 1 Bushing (SCH 40) Pipe O.D. No Bushings (DI) Inside Core Drilling I.D. Installation Depth (Min) GG Part Part
343 mm343 mm150 mm180 mm81 mm285 mm1,60 kg1 bar (10 m head)MULTI 200 NB
395 mm395 mm160 mm245 mm78 mm339 mm2,10 kg1 bar (10 m head)MULTI 250 NB19102
448 mm448 mm185 mm290 mm80 mm400 mm3,70 kg1 bar (10 m head)MULTI 315 NB19122
570 mm570 mm205 mm375 mm99 mm478 mm6,30 kg1 bar (10 m head)MULTI 400 NB19145
676 mm676 mm240 mm469 mm102 mm589 mm10,00 kg1 bar (10 m head)MULTI 500 NB
788 mm788 mm280 mm593 mm93 mm717 mm14,30 kg1 bar (10 m head)MULTI 600 NB
1003 mm935 mm450 mm700 mm120 mm1030 mm50,00 kg1 bar (10 m head)MULTI 700 NB
1125 mm1035 mm523 mm800 mm120 mm1440 mm75,00 kg1 bar (10 m head)MULTI 800 NB
1330 mm1264 mm495 mm1013 mm110 mm1400 mm105,00 kg1 bar (10 m head)MULTI 1000 NB
1525 mm1440 mm690 mm1200 mm130 mm1620 mm190,00 kg1 bar (10 m head)MULTI 1200 NB
1770 mm1640 mm800 mm1400 mm120 mm1840 mm270,00 kg1 bar (10 m head)MULTI 1400 NB
1860 mm1740 mm855 mm1500 mm120 mm1980 mm325,00 kg1 bar (10 m head)MULTI 1500 NB


GG PartPartDescriptionCase Qty.Case Wt.
MULTI 200 NB200 mm flange or headwall11,60 kg
MULTI 250 NB19102250 mm flange or headwall12,10 kg
MULTI 315 NB19122315 mm flange or headwall13,70 kg
MULTI 400 NB19145400 mm flange or headwall16,30 kg
MULTI 500 NB500 mm flange or headwall110,00 kg
MULTI 600 NB600 mm flange or headwall114,30 kg
MULTI 700 NB700 mm flange or headwall150,00 kg
MULTI 800 NB800 mm flange or headwall175,00 kg
MULTI 1000 NB1000 mm flange or headwall1105,00 kg
MULTI 1200 NB1200 mm flange or headwall1190,00 kg
MULTI 1400 NB1400 mm flange or headwall1270,00 kg
MULTI 1500 NB1500 mm flange or headwall1325,00 kg