Skip to content

How Long Should Your Sanitary Hose Assembly Last? It Can Depend on Physical Stresses.

May 13, 2014
Using a 90 Degree Elbow  to Limit the Stress on a Sanitary Hose

Using a 90 Degree Elbow to Limit the Stress on a Sanitary Hose

We provide a lot of sanitary hose assemblies into the biopharmaceutical, food, beverage and personal care industries.  Clients regularly ask us the question, “How long should I expect the hose to last?”.  Our answer is multifaceted and depends on how the hose is applied. Taking hose liner and process fluid compatibility as a given, there are two main factors that drive hose- mechanical stress and thermal stress.

Today we are going to look at mechanical stresses and how they affect the longevity of a sanitary hose.  Here are basic guidelines we use to ensure longevity in our sanitary hose assemblies.

  • Make sure you specify a hose that has a working pressure higher than that of the pressure of the fluid that is being pumped through the hose.  That sounds pretty simple, but we see hoses fail all of the time because of over pressurization and pulsation.
  • Avoid severe bends.  Bending the hose beyond its rated bend radius can cause kinks and premature failure- refer to our blog on live length and bend radius for more information on this subject.
  • Use elbows wherever possible.  Larger size hoses can become very heavy when filled with fluid- a 10 foot, 2” FGR hose can hold about 55 lbs. of water (plus the weight of the hose!).  If you have a long hose that is being piped from a horizontal run then allowed to bend 90 degrees down without being supported, severe stress will be put on the hose where it bends leading to premature failure.  Instead, put a 90 degree elbow on the horizontal run, then attach the hose.  We see many hoses fail because they are stressed right at the connection.
  • Keep the hose on a single plane.  Sanitary hoses are not designed to resist axial twisting and will fatigue prematurely if constantly submitted to axial torqueing.
  • Don’t stretch or compress the hose when installing.
  • Make sure you pick the correct hose material for the application.  Some sanitary hose material is more rugged than others.  If the sanitary hose assembly is going to be handled (connected/disconnected) on a regular basis, you want to pick a more ruggedly constructed hose than one that may be installed only once.  Sanitary hoses in dynamic applications (think filling machines) require special consideration.  Sanitary hoses with helical support wires in them generally do not do well in these applications as the wire tends to work harden and snap.
  • Make sure the hose in not torqued at installation.  If this is a problem, use a swivel connection.
  • Try to keep hoses off of the ground. Hoses that are left on the ground are bound to be run over by a forklift. While we love replacing your 15’ hose assembly every couple of months because it got crushed, try Rubberfab’s Golden Bridge Hose support to protect your investment.

So this covers the mechanical issues in sanitary hose assembly applications.  In future posts we will address the thermal and cleaning issues that can also affect the life expectancy of your hoses.  If you have any questions on this topic, contact one of our sales engineers.

No comments yet

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: