Expansion Reservoir 164mm DDC Acrylic by Barrow — 164 mm, black, model PBTT-BBB3130

Barrow Expansion Reservoir 164mm DDC Acrylic is a compact inline reservoir designed for custom PC liquid cooling loops that use a DDC pump form factor. The 164 mm acrylic tube provides visible coolant capacity and integrates directly with DDC-style pump mounts, enabling a neat, space-saving installation in systems where a traditional tall reservoir is impractical. Finished in black, this reservoir offers a low-profile solution for coolant storage, air separation and visual monitoring of fluid level within the loop.

Advantages

The acrylic construction combines clear visibility of coolant with a rigid, scratch-resistant surface suitable for standard cooling fluids. Its 164 mm length balances fluid capacity with compact dimensions, making it easier to fit into small or constrained cases. The DDC-compatible design simplifies mechanical integration with DDC pumps and mounting brackets, reducing the need for custom adapters. Black trim and fittings provide a discreet appearance that complements many build styles while concealing internal tubing or pump hardware.

Suitable for

• Compact custom water-cooling loops using a DDC pump form factor
• Systems with limited interior space where a vertical reservoir cannot be installed
• Builds requiring a visible inline reservoir for coolant level monitoring and air separation

Key specifications

• Reservoir material: acrylic tube with black end fittings
• Overall length: 164 mm
• Mounting compatibility: designed for integration with DDC-style pump mounts
• Orientation: inline/compact installation suitable for horizontal or short vertical runs
• Finish: black trim for discreet appearance

How to use

Install the reservoir inline between pump and radiator or as specified by your loop design, ensuring the DDC-compatible interface aligns with the pump mounting points. Securely fasten the end fittings and mounting brackets to prevent vibration and leaks. Fill the loop with the chosen coolant, then run the pump at low speed to circulate fluid while checking all connections for tightness and observing the reservoir for trapped air. Top up the reservoir until the coolant level stabilizes and perform leak testing before regular operation.

Recommendations

Use coolant formulations compatible with acrylic and compatible with your system materials; avoid aggressive chemicals or concentrated solvents. Periodically inspect the reservoir for sediment, discoloration or micro-scratches and perform routine coolant maintenance according to the coolant manufacturer’s guidelines. When mounting, allow clearance for tubing and pump access to simplify future maintenance.