Size Expandable Tight Weave Braided Sleeving in Swimming Pool Water Treatment Systems

In modern swimming pool water treatment systems, solid disinfectants—such as lime-based media or chlorine granules—play a major role in keeping the water clean and hygienic.
But these solid chemicals come with two classic engineering headaches:



  • They need to dissolve slowly and evenly in moving water


  • The granules must not escape into the system


To solve this reliably, many manufacturers are turning to a surprisingly simple but extremely effective structure:
a large expandable Tight Weave Braided Sleeving supported by an internal metal spring.

This setup looks simple—but mechanically, it solves almost every challenge in one go.

PET Tight Weave Expandable Braided Sleeving

1. Why This Structure Is Needed

One of our customers in the water treatment industry needed to introduce lime-based disinfectant granules into a circulating pool system. Their requirements were clear:

  • The media must dissolve gradually
  • Water must penetrate freely
  • No granules should leak out
  • The container must be flexible, corrosion-resistant, and easy to fill
  • And it needed to hold a large volume of media

Conventional rigid filter tubes failed—either too costly or too inflexible.

That's where our large-diameter, expandable PET Tight Weave Braided Sleeving came in.
By combining it with a coil spring inside, the customer created a simple, low-cost, and highly efficient dissolving cylinder.


2. How the System Works

A Spring-Supported Braided Sleeve Acting as a  "Permeable Filter Cartridge"
The full assembly has three functional layers:
1) PET Tight Weave Braided Sleeving (Outer Layer)
  • Allows water to flow in and out easily
  • Tight weave structure prevents any granules from escaping
  • Resistant to abrasion, chemicals, and long-term water immersion
  • Flexible and suitable for irregular installation spaces
2) Metal Coil Spring (Support Layer)
  • Expands the sleeving to the required diameter
  • Maintains a round, open interior flow path
  • Prevents collapse under water pressure
  • Ensures stable and consistent water penetration
3) Lime-Based Disinfectant Granules (Inner Layer)
  • Filled inside the spring cavity
  • Water flows through, gradually dissolving the media
  • Dissolved disinfectant is carried into the pool water
  • Larger granules remain safely inside the Tight Weave Braided Sleeving

3. How the System Actually Operates


Water Penetration → Controlled Dissolution → Safe Release

Here's the flow in simple terms:

  • Water circulates around the sleeve
  • Water penetrates through the braided mesh
  • Water enters the spring-supported cavity
  • Granules slowly dissolve
  • Disinfectant releases into the water flow
  • Undissolved granules stay inside the sleeve—no leakage
This structure provides a perfect balance of:
  • Filtration
  • Containment
  • Controlled release
Exactly what a dissolving media system needs.

4. Why Large Expandable Tight Weave Braided Sleeving Is Essential


Water treatment systems often require large media volume, and most standard sleeving only expands to 20–50 mm.
MJ-IST high-expand PET Tight Weave Braided Sleeving offers:

  • Expansion ratios up to 1:3 or more
  • Maximum expanded diameters of 100–150 mm
  • Enough space for both the spring and a large amount of media
  • Lightweight, flexible, and chemically resistant structure
  • Much lower cost than custom plastic or metal filter housings
This makes it ideal not just for cable protection—but for any filtration or dissolving media container.

5. Why Customers Choose PET Tight Weave Braided Sleeving for Pool Applications


✔ Excellent chemical resistance
Stable even in alkaline environments created by lime media.

✔ Superior water permeability
The tight yet open weave allows multi-directional water flow.

✔ Lightweight and flexible
Easy to fill, install, clean, and replace.

✔ Highly cost-effective
Cheaper and easier than molded or machined filter housings.

✔ Customizable mesh density
Allows designers to match weave tightness to media granule size.

A Simple but Smart Solution for Water Treatment Systems
This case shows how Tight Weave Braided Sleeving, when combined with a spring, becomes far more than a cable protection product.
The structure:

  • Works like a flexible filter tube
  • Maintains shape under water pressure
  • Prevents media leakage
  • Ensures smooth, controlled dissolving behavior

It's a smart, durable, and cost-efficient solution widely used in:

  • Swimming pool systems
  • Water treatment plants
  • Chemical dosing equipment
  • Any application requiring controlled dissolution of granular media