Braided Packing vs Mechanical Seals

From rendering to manufacturing, industries have been debating the best industrial packing solution for decades. Two of the biggest contenders in this race are mechanical seals and braided packing — each have their own unique characteristics that make them suited for their sealing tasks, but which solution is the overall better one is a topic of perennial debate.

In this article, we’ll walk you through both mechanical seals and braided packing, and run through the benefits and drawbacks of each.

Mechanical Seals

Mechanical seals consist of two bound pieces of metal, kept in place and in operation via pressure and the fluid from the pump being sealed. Each seal is kept apart from one another by being interspersed with small quantities of fluid, this fluid filling in and/or creating small gaps between each seal. This not only prevents the seals from rubbing against one another inside the stuffing box and creating friction, but it helps keep the seals lubricated automatically, as the fluid itself acts as a constant lubricant.

Mechanical seals operate off of the fluid that surrounds them during active pumping. This fluid not only keeps the individual seals from making contact with each other and the shaft, but also absorbs heat so as to take pressure off of both the shaft and the seals. As this liquid is necessary for the proper function of mechanical seals, leakage is unavoidable — it can be argued that mechanical seals repurpose leakage and turn it into a helpful positive.

However integral to mechanical seals leakage is, it’s impossible to mitigate in its entirety without outside cleanup operations. Some jobs can produce less than others, but the exact amount of leakage you can expect depends heavily on the job at hand. Most jobs will have a not-insignificant amount of leakage, and it will need to be handled properly and at regular intervals so it does not become a safety hazard. Mechanical seals are also at the higher end in terms of price, meaning they’re often seen as a more premium packing solution.

Braided Packing

Packing rings are inserted directly into the stuffing box, and helps mitigate — not prevent — leakage over time. Packings prevent the lion’s share of leakage from reaching the outside of the pump by being placed under pressure while inside the stuffing box, while a thin layer of liquid makes its way underneath the packings and eventually finds its way outside the pump.

Braided packing is not designed to totally prevent leakage, rather it’s designed to make it more manageable. Braided packing needs to be adjusted regularly, as much as once per day, to maintain a proper seal and to maximize leakage mitigation.

One of the biggest advantages most plants see in braided packing is its price point. Braided packings are typically less expensive than mechanical seals due to the more inexpensive materials used in their creation. Where mechanical seals require precisely-made sheets of metal for fabrication, braided packings use braided fabric-like substances to provide a more economical solution to industrial sealing.

One of the biggest drawbacks of braided packing is its average lifespan. Friction on the shaft and the nature of the materials in their construction means that braided packings are less durable than mechanical packings, and as a result they need much more frequent replacement.

I Need Something Long-Lasting & Affordable — What Do I Pick?

RainsFlow packagingThe secret for a long-lasting, yet affordable industrial packing solution won’t be found in either mechanical seals or braided packing — RainsFlo offers the cost-effectiveness of braided packing with far superior durability, which means a 3-4x longer packing lifetime without adjusting your budget.

RainsFlo’s patented packing design allows for self-lubrication, the more pressure the packings are put under, the more lubrication is released onto the shaft — this increases the lifetime of the packings, but also boosts the longevity of the shaft itself. The structure of RainsFlo means only the lubrication that is needed is released automatically, keeping things in the stuffing box running smoothly with a far reduced need for human intervention.