MULTI BD Straight Flap Valves — MULTI BD Series

Protection against drainage & sewage backwater/flooding. Straight Flap Valve 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 3.94" - 7.87"


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

MULTI BD Straight Flap Valves MULTI BD 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. Resillient
  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
8.35 in8.66 in1.97 in4.33 in2.17 in7.68 in1.10 lbs1 bar (33 ft head)MULTI 100 BD19041
9.92 in9.84 in2.17 in4.92 in2.60 in9.06 in1.54 lbs1 bar (33 ft head)MULTI 125 BD
9.92 in11.22 in2.17 in6.30 in2.60 in10.24 in2.43 lbs1 bar (33 ft head)MULTI 150 BD19061
14.65 in13.39 in2.76 in7.87 in2.95 in12.40 in3.53 lbs1 bar (33 ft head)MULTI 200 BD19081


GG PartPartDescriptionCase Qty.Case Wt.
MULTI 100 BD190414" flange or headwall11.10 lbs
MULTI 125 BD5" flange or headwall11.54 lbs
MULTI 150 BD190616" flange or headwall12.43 lbs
MULTI 200 BD190818" flange or headwall13.53 lbs