Tideflex Valves vs Flap Valves

blocked-flap-valve-tideflex

Tideflex Valves vs Flap Valves

Key Benefit: TOTEX Winner!

MeasurIT are increasingly called upon by end users to provide Tideflex valves to replace faulty flap valves (see case studies here and here). However, it can sometimes be difficult for designers to justify the specification of a Tideflex valve when construction and council budgets become involved. We maintain that the capital outlay on a Tideflex far outweighs the operational costs of a flap valve. Here are some facts for peace of mind for those considering their options.

Key Features

  • Duckbill design - variable opening
  • Rubber construction - flexible, durable & strong
  • Tideflex Technologies are the original inventor and manufacturer of the duckbill check valve

Key Advantages

  • Self-clearing of debris so eliminate potential blockages 
  • Do not warp, freeze or corrode so maintain long-term function
  • Thirty years of proven field operation, research and development, and continued engineering enhancements - the nature of its construction means that the design cannot be copied

Key Benefits

  • Free draining - no upstream flooding issues
  • No maintenance - saving operational time and money
  • 25+ years service life - long-term capital cost savings
  • Reliable, proven track record - no unpleasant surprises

Flap valve design
While flap valves have traditionally been viewed as a simple solution to a simple problem - backflow prevention - the maintenance department of any local council have countless examples of where the practical implementation is far more complex. Anywhere an outfall occurs in a coastal or river location, it will be subject to the influence of wind and water action. While flap valves operate well on outfalls located where sand, mud, silt, stones and other debris cannot reach them, in locations where this is not possible they tend to fail time and again. Either the valve is unable to open or it is unable to close fully - both scenarios resulting in flooding upstream and other negative consequences, depending on the drainage system design. Below is a small selection of the types of scenarios that can occur - perhaps you have seen similar situations.

Flap valve routinely buried by shifting beach sand leading to upstream flooding.

Flap valve routinely buried by shifting beach sand leading to upstream flooding.

Flap valve unable to function due to shingle beach constraints

Flap valve unable to function due to shingle beach constraints

Another flap valve unable to function due to typical beach sand/stones

Another flap valve unable to function due to typical beach sand/stones

Silt blocked this pumped outfall - pumps deadheaded and emergency response team broke the flap to clear the line.

Silt blocked this pumped outfall - pumps deadheaded and emergency response team broke the flap to clear the line.

Residents have attached ropes to these flap valves for manual operation due to ongoing problems with blockages

Residents have attached ropes to these flap valves for manual operation due to ongoing problems with blockages

Ad hoc flap valve protection "installed" presumably to prevent tampering and rocks interfering with operation.

Ad hoc flap valve protection "installed" presumably to prevent tampering and rocks interfering with operation.

Flap valves wedged open to ensure free draining of upstream system, but useless now in preventing backflow.

Flap valves wedged open to ensure free draining of upstream system, but useless now in preventing backflow.

Find the outfall! Cleverly disguised, but not so effective...

Find the outfall! Cleverly disguised, but not so effective...

Even with the best of designs, real-world scenarios can be unexpected!

Even with the best of designs, real-world scenarios can be unexpected!

Flap valve maintenance effort & cost
While flap valves may appear to be a cost-effective solution due to their widespread availability, ease of installation and low capital cost, many an end user has found the old adage "penny-wise and pound-foolish" to be an apt description. As can be seen from the above photos, over the lifetime of a particular flap valve many different maintenance scenarios may arise that lead to on-going costs and even replacement expenditure.

Maintenance costs may include, but not be restricted to, the following:

  • plant to clear blockages - backhoe/mini digger/pump/generator/truck,
  • manpower - general operative/driver/foreman/engineer,
  • environmental testing of excavated material/dredging license,
  • disposal of excavated material,
  • upstream flooding issues due to flap valves being stuck closed or open,
  • restoration after process upsets due to flooding & saltwater intrusion into WWTWs,
  • bad publicity

Here are a few of our favourite maintenance photos....

It can be a long way to go to reach a flap valve in some locations....

It can be a long way to go to reach a flap valve in some locations....

Excavators can be needed as often as once a week in seasons of high winds at some coastal locations

Excavators can be needed as often as once a week in seasons of high winds at some coastal locations

Excavator teeth marks.... And a handy yellow arrow painted on the wall for finding the regularly buried valve.

Excavator teeth marks.... And a handy yellow arrow painted on the wall for finding the regularly buried valve.

Not exactly what you want to be seeing in your outfall drain - or have to be clearing out!

Not exactly what you want to be seeing in your outfall drain - or have to be clearing out!

Here are just a few examples of our Tideflex valves operating under circumstances that a flap valve would be unable to cope with adequately.

Half-buried, a Tideflex valve still manages to discharge and will eventually clear itself.

Half-buried, a Tideflex valve still manages to discharge and will eventually clear itself.

Another Tideflex valve carving a name for itself on a beach with shifting sand

Another Tideflex valve carving a name for itself on a beach with shifting sand

Not even a stony path can stop discharge from a Tideflex!

Not even a stony path can stop discharge from a Tideflex!

Whether it is silt or water surrounding it, a Tideflex valve always manages to discharge the upstream flow.

Whether it is silt or water surrounding it, a Tideflex valve always manages to discharge the upstream flow.

The correct way to handle an unexpected football situation - business as usual for a Tideflex valve.

The correct way to handle an unexpected football situation - business as usual for a Tideflex valve.

Tideflex check valves have proven time and again that they are able to handle the various trials and tests of harsh conditions, extreme siltation and unexpected situations. MeasurIT have over 20 years experience in installing Tideflex products in new build and retrofit projects. Why not consider the whole-life cost of your outfall and make Tideflex your first choice for peace of mind and sensible budget expenditure? Your maintenance staff and local area residents will thank you for it for decades to come!