Unvented Group Multibloc Expansion Vessel Connection 22mm - 3Bar PRV 6Bar SRV

Description

The Inta Unvented Group Multibloc controls inlet pressure to unvented hot water storage systems in a single compact fitting. It combines a 3 bar pressure reducing valve (PRV), a 6 bar safety relief valve (SRV), an integral check valve and a cleanable 300-micron filter, with a balanced cold feed connection built into the manifold body.

Finished with a 3/4″ expansion vessel connection, the unit is designed to simplify installation on unvented cylinders where a compression-style manifold fitting is preferred over push-fit. It conforms to BS EN 1567 and CPR standards, supporting a compliant installation under UK Building Regulations Part G3.

3 bar

PRV Factory Setting

6 bar

SRV Factory Setting

16 bar

Max Inlet Pressure

80°C

Max Working Temp

22mm

Main Connection

300μm

Filter Mesh Size

Important Safety Information

A tundish is not included with this unit and must be fitted separately for regulatory compliance. Installation must be carried out by a G3-qualified engineer, and the safety relief valve must discharge via the tundish in line with Building Regulations Part G3.

Please Note

This is the multibloc connection variant of Inta's unvented group set. If your installation uses a push-fit 22mm connection instead, a push-fit version of this same valve set is available separately — check which fitting style your pipework requires before ordering.

Good to Know

The integrated balanced cold feed connection helps maintain even pressure across the hot and cold supplies feeding the cylinder, supporting more consistent performance at outlets.

All-in-One Multibloc Design

Combines a PRV, SRV, check valve and filter in one manifold body, reducing the number of separate fittings needed on an unvented installation.

Balanced Cold Feed Connection

An integrated balanced cold feed helps keep pressure consistent between the hot and cold supplies serving the cylinder.

Expansion Vessel Ready

A 3/4″ expansion vessel connection is built into the manifold, simplifying the link to a compatible expansion vessel.

Non-Adjustable Safety Settings

The PRV is factory set to 3 bar and the SRV to 6 bar, giving consistent, tamper-resistant protection for the cylinder and system.

Removable Filter

The 300-micron stainless steel mesh filter can be taken out for cleaning without disturbing the rest of the installation.

Compliant Construction

Conforms to BS EN 1567 and CPR standards, supporting use in compliant unvented hot water installations.

Valve Specification

Manufacturer

Inta

Connection

22mm compression/multibloc (main), 3/4″ expansion vessel connection

Max. inlet pressure

16 bar

PRV factory setting

3 bar

SRV factory setting

6 bar

Max. working temperature

80°C

Filter

300 micron, stainless steel, removable

Dimensions (H x W)

110mm x 133.2mm

Approval

Conforms to BS EN 1567 and CPR standards

Included Components

Included

Pressure reducing valve (PRV), safety relief valve (SRV), non-return check valve, 300-micron stainless steel filter

Not included

Tundish (required separately for regulatory compliance)

Is a tundish included with this unit?

No. A tundish is required for regulatory compliance but is not included, so it must be sourced and fitted separately by the installer.

What connection type does this version use?

This is the compression/multibloc connection variant. A push-fit version of the same PRV/SRV valve set is available separately if your pipework uses push-fit fittings instead.

Does it include an expansion vessel?

No. The unit has a built-in 3/4″ connection for linking to a suitable expansion vessel, which is supplied separately.

Can the PRV or SRV settings be changed on site?

No, both are factory set and non-adjustable: the PRV at 3 bar and the SRV at 6 bar.

Who is qualified to install this unit?

Unvented hot water systems fall under Building Regulations Part G3 in England and Wales, so installation and commissioning should only be carried out by a G3-qualified engineer.

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