# How to Choose an Inflatable Pipe Plug

Canonical: https://reliancetrenchless.com/resources/inflatable-pipe-plug-selection-guide

Language: English

Choose an inflatable pipe plug by its task, measured pipe bore, access conditions and model-specific limits. Confirm inflation pressure and back pressure separately, and specify whether a bypass is required. A nominal size or family name is not enough to establish suitability.

This guide helps prepare a purchase enquiry. It does not prescribe inflation settings, a pressure-test procedure or a restraint design. Use the confirmed instructions for the exact product and a site-specific safety plan prepared by qualified personnel.

## 1. Separate isolation, bypass and testing requirements

Begin with the job rather than a catalogue code. Temporary isolation, flow diversion and pipeline testing are different requirements. Write down what needs to be blocked or tested and whether flow has to continue through a planned bypass arrangement. If the task is a localized patch repair instead, review the repair packer equipment rather than assuming a sealing plug will do the same work.

Reliance groups multi-size plugs, single-size plugs and testing plugs within its pipe-plug family. Use that overview to shortlist the relevant product type, then check the particular model. The family descriptions are an introduction, not approval for every pipe material, test method or pressure condition.

Use the job to shortlist a product type; confirm the exact configuration separately.

| Product type | Starting point | Questions for the supplier |
| --- | --- | --- |
| Multi-size pipe plugs | An application within a published fit range | Which model fits the measured bore, and is bypass required? |
| Single-size pipe plugs | A plug selected for a nominal pipe size | What actual bore and access conditions are permitted for this model? |
| Testing plugs | A proposed pipeline test or stated testing task | What fit dimensions, test conditions and limits apply to this configuration? |

Sources:
- [Reliance pipe plugs and testing: product-type comparison](https://reliancetrenchless.com/products/pipe-plugs-and-testing)
- [Reliance single-size plugs: nominal sizes and model-specific information](https://reliancetrenchless.com/products/single-size-pipe-plugs#product-guide)
- [Reliance testing plugs: dimension definitions and brochure table](https://reliancetrenchless.com/products/testing-plugs#product-guide)

## 2. Keep nominal size, measured bore and product dimensions distinct

Record the measured internal diameter where the plug will sit, pipe material and surface condition. A nominal pipe size or the digits in a model name are not a substitute for a confirmed fit range. If the bore is irregular or the pipe changes size, send a sketch and measurements rather than relying on a single nominal value.

The deflated product dimensions describe another constraint: access. Include the entry opening, insertion space and any bends or restrictions. Ask for the dimensions of the complete configuration, including the relevant fittings and accessories. A plug can belong to the intended pipe-size category while still requiring an access assessment.

The testing-plug product page specifically notes that the brochure’s description dimension is not labeled as a supported pipe range. Confirm that dimension’s meaning before comparing it with a pipe measurement. Keep the original source and column heading with any dimensions sent for review.

Sources:
- [Reliance multi-size plugs: source notes, bypass and specifications](https://reliancetrenchless.com/products/multi-size-pipe-plugs#product-guide)
- [Reliance single-size plugs: nominal sizes and model-specific information](https://reliancetrenchless.com/products/single-size-pipe-plugs#product-guide)
- [Reliance testing plugs: dimension definitions and brochure table](https://reliancetrenchless.com/products/testing-plugs#product-guide)

## 3. Confirm inflation pressure and back pressure separately

Inflation pressure is the pressure inside the inflatable plug. Back pressure acts against the plug from the pipe contents and can push it along the pipe. These terms describe different conditions; a catalogue inflation value does not establish the permitted back pressure.

Reliance’s multi-size documents use separate columns for inflation pressure and maximum back pressure. Ask for the limits and instructions for the selected model, configuration and pipe conditions. Do not infer a whole-range rating from a brochure headline, another model or a competing manufacturer’s product.

For the enquiry, record the expected operating or testing conditions with units and explain how the pressure information was obtained. If only a water level, test specification or incomplete site measurement is available, share the original information and ask for technical review. Do not guess a setting from this article. Restraint, installation and pressure management remain part of the approved site procedure.

Sources:
- [Reliance multi-size plugs: source notes, bypass and specifications](https://reliancetrenchless.com/products/multi-size-pipe-plugs#product-guide)
- [PlugCo: inflation pressure and back pressure (terminology only; not Reliance ratings)](https://www.plugco.net/pipe-plug-inflation-presure-and-back-pressure)

## 4. Specify what the bypass must do

The published multi-size range distinguishes MS plugs without bypass from MSBP bypass plugs. State whether flow diversion is required, what needs to pass through the planned arrangement and which connections or site restrictions must be considered.

The word “bypass” alone does not establish a flow capacity or a complete pumping arrangement. Ask the supplier to confirm the passage and connection details for the quoted configuration and identify any separate equipment needed. Do not assume an otherwise similar non-bypass model can be substituted.

Likewise, request an itemized accessory list. The brochure describes a pressure gauge and air hose and lists protective sleeves separately. The quotation should confirm what is supplied for your order rather than leaving the buyer to infer the package from a photograph or an accessory mentioned elsewhere.

Sources:
- [Reliance multi-size plugs: source notes, bypass and specifications](https://reliancetrenchless.com/products/multi-size-pipe-plugs#product-guide)

## 5. Compare the source documents—not just the numbers

Reliance’s product pages retain the original brochure and spreadsheet. The multi-size page explicitly records differences in some dimensions, weights and pressure values. These differences are not resolved by choosing the more favorable value or silently assuming that one document is newer.

Include the model, document name and row in your request. Ask for the applicable specification, drawing, configuration and operating instructions in writing. The testing-plug page also explains that the shared spreadsheet does not contain TP model rows; absence from that spreadsheet does not mean there are no testing-plug specifications.

Do not proceed on a pressure or fit assumption while a relevant discrepancy remains unresolved. Keep the confirmed documents with the order, and request any inspection or acceptance documentation needed for your project. A general catalogue description does not establish a certification or suitability for a specific service.

Sources:
- [Reliance multi-size plugs: source notes, bypass and specifications](https://reliancetrenchless.com/products/multi-size-pipe-plugs#product-guide)
- [Reliance testing plugs: dimension definitions and brochure table](https://reliancetrenchless.com/products/testing-plugs#product-guide)
- [Reliance quality and project-document enquiries](https://reliancetrenchless.com/quality)

## A better starting point than “send a price for a pipe plug”

Describe whether the job is isolation or testing, give the measured bore and access constraints, and explain whether flow needs to be diverted. Include the pressure information you actually have, the candidate model or document you reviewed, quantity and destination.

Ask the supplier to identify the configuration to evaluate and confirm fit, separate pressure limits, bypass connections and supply scope. Where conditions are not yet known, mark them as unknown in the enquiry. This is a purchasing example, not a completed application, model recommendation or instruction to operate a plug.

## What to include in your enquiry

- Task: temporary isolation, flow diversion or pipeline testing; identify the proposed test requirements.
- Measured pipe internal diameter, material and local condition; note nominal size separately.
- Entry opening, insertion space, access route and any bends or restrictions.
- Expected back-pressure or test conditions, units and source of the information; identify what is not yet measured.
- Bypass requirement, intended flow arrangement, available connections and constraints.
- Candidate model and document/row; request confirmation of fit and separate inflation/back-pressure limits.
- Quantity, destination, requested delivery date, accessory list and any required inspection documents.

[Request a pipe plug configuration review](https://reliancetrenchless.com/contact?product=MultiSizePipePlugs)

The contact form opens an email draft for the visitor to review and send; it does not confirm delivery.