---
product_id: 41609852
title: "HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray"
brand: "flextrol"
price: "$152.58"
currency: USD
in_stock: false
reviews_count: 8
url: https://www.desertcart.us/products/41609852-highcraft-gui50-hydronic-expansion-tank-for-heating-system-carbon-steel
store_origin: US
region: United States of America
---

# 210°F Max Temp 4.8 Gal Capacity 60 PSI Max Pressure HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray

**Brand:** flextrol
**Price:** $152.58
**Availability:** ❌ Out of Stock

## Summary

> 🛠️ Elevate your heating system’s safety with HIGHCRAFT’s powerhouse expansion tank!

## Quick Answers

- **What is this?** HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray by flextrol
- **How much does it cost?** $152.58 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.us](https://www.desertcart.us/products/41609852-highcraft-gui50-hydronic-expansion-tank-for-heating-system-carbon-steel)

## Best For

- flextrol enthusiasts

## Why This Product

- Trusted flextrol brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Heat Ready:** Handles temperatures up to 210°F, keeping your system stable under high-heat conditions.
- • **Built to Last:** Solid carbon steel with exclusive polypropylene liner ensures unmatched durability and leak resistance.
- • **Pressure Perfect:** Operates safely up to 60 PSI, preventing dangerous pressure build-up in your heating system.
- • **Certified Confidence:** Factory leak tested and NSF61 certified for guaranteed safety and reliability.
- • **Low Profile, High Performance:** Compact design with full membrane depth extends diaphragm life and reduces maintenance.

## Overview

The HIGHCRAFT GUI50 Hydronic Expansion Tank is a robust 4.8-gallon carbon steel solution designed to protect heating systems by preventing pressure build-up and leaks. Featuring a polypropylene liner, SBR rubber diaphragm, and a durable epoxy-polyester coating, it operates safely up to 60 PSI and 210°F. Its low-profile design maximizes diaphragm lifespan, while factory leak testing and NSF61 certification ensure top-tier reliability.

## Description

What is Hydronic Expansion? Hydronic expansion tanks are diaphragm type tanks designed to keep system pressures below relief valve settings. Hydronic expansion tanks absorb the expansion of water in residential or commercial hydronic (forced hot water) heating and cooling systems. Without hydronic expansion tanks, the system will quickly over-pressurize resulting in added stress to the various system components. Hydronic expansion tanks protect safety valves from failing or wearing out quickly, avoids valve stem and ball seal leaks, prevents wasted BTU’s and vastly extends water heater life. Technical Features • Certified synthetic SBR rubber diaphragm • MIG welding eliminates interior rough spots and sharp edges • Each tank is factory leak tested to ensure tank integrity • All diaphragms designed to maximize drawdown • External baked epoxy-polyester coating provides a durable appliance finish • Welded side outlet allows easy and quick installation • Protected pre charge valve eliminates potential leak path • Low profile tank design with full membrane depth eliminates stretching of diaphragm, providing increased life cycle Additional Description • Shell: Carbon Steel • Connection: Carbon Steel • Diaphragm: SBR Synthetic Rubber • Color: Gray ⚠ California Proposition 65 Warning: This product is known to the state of California to cause cancer, or other reproductive harm. For more information, go to www.p65warnings.ca.gov.

## Features

- Protects Your Heating Systems; PreVents Dangerous Pressure Build up; Eliminates Potential Leak Path
- Features a Solid Carbon steel Construction with an Exclusive Polypropylene Liner, MIG Welding, SBR Rubber Diaphragm, and External Baked Epoxy-Polyester Coating for Superior PerFormance
- Each Tank is Factory Leak Tested and NSF61 Certified
- Max Operating Pressure 60 PSI; Temperature 210°F
- Low Profile Tank Design with Full Membrane Depth Eliminates Stretching of Diaphragm, Providing Increased Life Cycle

## Technical Specifications

| Specification | Value |
|---------------|-------|
| Brand | HIGHCRAFT |
| Color | Gray |
| Mounting Type | internal |
| Is Electric | No |
| Manufacturer | Highcraft |
| UPC | 804595130759 |
| Global Trade Identification Number | 00804595130759 |
| Part Number | GUI50 |
| Item Weight | 6.8 pounds |
| Product Dimensions | 12 x 12 x 16 inches |
| Item model number | GUI50 |
| Size | 4.8 Gallons |
| Item Package Quantity | 1 |
| Number of Handles | 1 |
| Included Components | Hydronic Expansion Tank |
| Batteries Included? | No |
| Batteries Required? | No |
| Warranty Description | 1 Year |

## Product Details

- **Brand:** HIGHCRAFT
- **Color:** Gray
- **Mounting Type:** internal
- **Is Electric:** No
- **Manufacturer:** Highcraft

## Images

![HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray - Image 1](https://m.media-amazon.com/images/I/61leex5vuhL.jpg)
![HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray - Image 2](https://m.media-amazon.com/images/I/71ERc7P8W-L.jpg)
![HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray - Image 3](https://m.media-amazon.com/images/I/615-ATBrZDL.jpg)
![HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray - Image 4](https://m.media-amazon.com/images/I/61rc9Dy6AsL.jpg)
![HIGHCRAFT GUI50 Hydronic Expansion Tank for Heating System Carbon Steel Grey Holds 4.8 Gal, 4.8 Gallons, Gray - Image 5](https://m.media-amazon.com/images/I/61Ttbo7lhXL.jpg)

## Available Options

This product comes in different **Size** options.

## Customer Reviews

### ⭐⭐⭐⭐⭐ Works great. Inlet was smaller than expected but easily remedied ...
*by A***  on February 24, 2018*

Works great. Inlet was smaller than expected but easily remedied with a reduced. The seam around the middle is big and conflicted with my support bracket, but that's ok.

### ⭐⭐⭐ First time install, leaking water from the shell.
*by J***D on February 18, 2023*

First time install, leaking water from the shell.

### ⭐ junk
*by A***R on September 16, 2020*

The item description states 3/4 inch fitting but it is only 1/2 inch. I like to rely on Amazom to provide accurate information. This error caused me to take time during Covid-19 to go to the hardware store for a reducer. The cost was not the issue. The effort involved was. The product was well made and works as it should. No complaints there.UPDATE: failed after just a few monthe...filled with water and became useless

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*Product available on Desertcart United States of America*
*Store origin: US*
*Last updated: 2026-02-10*