# Plumbing fitting DANFOSS 003L0126 — return valve RLV-S 20 straight, 3/4" connection

**URL:** https://aio.lv/en/product--danfoss-003l0126--12364657
**Data updated:** 2026-04-26 18:53 (EEST)
**Category:** Heating Radiators
**Manufacturer:** DANFOSS
**Manufacturer code:** 003L0126
**EAN:** 5702420035857
**Warranty:** 2 Years
**Availability:** Out of stock

## Summary description

DANFOSS 003L0126 is a plumbing fitting identified as a straight return valve RLV‑S 20 with a 3/4" connection. Supplied as a single unit (1 pc), it is intended for use in heating and hydronic systems to control return flow. Suitable for installation in residential or commercial boiler and radiator circuits where a compact straight return valve is required.

## Long description

DANFOSS 003L0126 is a straight return valve RLV‑S 20 with a 3/4" connection designed for use in heating and hydronic systems. Supplied as a single unit, this compact plumbing fitting allows controlled return flow in boiler and radiator circuits and is intended for installations where a straight-line valve body and reliable flow regulation are required.
Advantages
The RLV‑S 20 straight return valve provides stable return flow control with a compact straight-line design that simplifies installation in confined spaces. Constructed to meet typical industry durability standards for plumbing fittings, it offers straightforward integration into residential and commercial hydronic circuits and is supplied ready for connection with a 3/4" threaded interface.
Suitable for
Residential central heating return lines
Commercial boiler return circuits
Radiator and convector return connections
Hydronic loop systems requiring a compact straight valve
When it may not be suitable
This valve may not be suitable for systems that require angled or angle-type fittings, where space or piping orientation prevents a straight inline connection. It may also be inappropriate for systems with connection sizes other than 3/4" or where additional integrated features (such as built-in strainers, sensors, or motorized actuation) are required.
Key specifications
Valve type: straight return valve (RLV‑S 20)
Connection size: 3/4" threaded inlet/outlet
Application: heating and hydronic return lines
Unit supplied: single piece
How to use
Install the RLV‑S 20 in the return pipe of the heating circuit in the straight orientation, ensuring compatible 3/4" threaded connections and appropriate sealing (thread tape or sealing compound) as per installation practice. Tighten to recommended torque for the system piping material, then purge air from the system and check for leaks. Adjust system balancing and flow rates according to the hydronic design and commissioning procedures applicable to the installation.
What to consider before purchase
Verify the connection diameter and thread type on the existing piping is 3/4" and compatible with the valve.
Confirm the straight valve body fits the available space and piping orientation.
Ensure the valve functional characteristics meet system flow and balancing requirements.
Usage recommendations
Use appropriate sealing materials on threaded joints, perform a pressure and leak test after installation, and follow local regulations and manufacturer guidance when integrating the valve into heating and hydronic systems.

## Specifications

| Feature | Value |
|---|---|
| Easy to install | Yes |
| Quantity per pack | 1 pc(s) |

## FAQ

### What payment options are available?

AiO.lv offers several payment methods: Bank transfer. All transactions are 100% secure and encrypted.

### Can this product be purchased for a company (with VAT)?

Yes. AiO.lv works with legal entities in Latvia and across Europe. The product price already includes VAT. For certain product categories, as well as for companies from other EU countries with a valid VAT number, a 0% VAT rate may apply. We issue the invoice immediately after the order is placed, support electronic BIS invoices, and automatically generate all necessary accounting documents. You can complete the purchase for a company online — simply select the company profile and choose bank transfer as the payment method during checkout.

### What is the warranty period?

All DANFOSS products come with an official 2 Years warranty. It covers all manufacturing defects and malfunctions that may occur during use. The warranty is valid at all authorized DANFOSS service centers and through AiO.lv

### Can the product be returned after purchase?

Yes, you can return the product within 14 days of purchase if you bought it as a consumer (not a legal entity). Returns are possible without giving any reason — the main condition is that the product retains its original appearance and full set of accessories. We will make the process as simple and convenient as possible: just contact our customer support team, and we will help you arrange the return.

### Where should I contact for warranty service?

For warranty-related questions you can contact the AiO.lv (SIA VSPRO) customer support team. More information about warranty service: https://aio.lv/en/warranty

## Image

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