Sometimes we develop myths about certain technologies. None are more frustrating than the belief that floats on continuous float level sensors get stuck.
We like to get as much industry feedback as we can. Trade shows are a good opportunity to do this. Over the last several years attending OTC in Houston, many have told us that they resist using float level transmitters, or magnetic level probes, because they’re worried the float will get stuck.
So we decided to debunk the myth here. Bottom line, we have 10,000 + units in the field (most from long time customers), in anything from wastewater lift stations to oil and gas mud tanks, and the floats never get stuck.
That’s not to say it isn’t possible, but in the applications where this sensor technology works well, it just isn’t happening. This is due to three important factors:
The Space Between
The big factor at play here is the amount of space between the inner diameter of the float and the stem. Some manufacturers have designed their units so that the space between the two is very tight. This greatly increases the risk of the float getting stuck. When we’re concerned about the possibility of a sticking float, we open up the gap to allow solids to pass through.
Some applications seemingly pose a substantial risk of a stuck float. For example, the United States Coast Guard has had great success with our FLX sensors installed in sewage tanks on their ships. We designed a special float and collar to allow for greater-than-normal distance between the stem and the floats. So far, so good.
The space between the inside of the float and the stem is critical, and we have found the perfect distance for a variety of applications.
Heavy Floats
Thankfully, buoyancy isn’t a function of weight, but density. That’s good news, because a lightweight float is at greater risk of sticking in viscous environment.
The more viscous the liquid, the heavier the float should be. If it’s not heavy enough, it could get stuck on build-up.
For applications with viscous liquids (like mud), we recommend a larger, heavier float. These floats are capable of powering through build-up. The float and stem become self-cleaning; as the float scrapes up once side of the stem and down another.
Application Is Always King
While we are confident that our magnetic float level transmitters will perform well in many applications, we will never recommend a model for an application that simply won’t work. For example, a magnetic float level sensor should never be installed in a sticky media where thick build up is a guarantee. While our floats may work for a while, they will eventually get stuck. In cases like these, we have other technologies that perform well.
If you have an application where other sensing technologies have failed, we recommend reconsidering magnetic float level sensors. They are not affected by factors that plague popular non-contact solutions such as foam, vapors, temperature gradients, tank material, or dielectric constant. Be careful not to rule out a reliable level sensing solution due to a baseless stigma.
Please contact us today and we’ll discuss your application to see if a continuous float level transmitter is right for you, and the merits of any alternative options.
top photo credit: Fifth World Art via photopin cc
