Variations and optional devices for rubber expansion joints - Protective covers | Macoga

MACOGA Protective Covers – Elastomeric Expansion Joint Protective Covers

Protective covers are optional external accessories for MACOGA elastomeric expansion joints. They are specified when the elastomer body is exposed to mechanical contact, external abrasion, UV radiation, or thermal hazards from adjacent equipment. These covers do not alter the expansion joint’s primary function and do not replace anchors, tie rods, or movement-limiting devices.

Cover Types

• Expanded metal covers: Perforated metal shields designed to protect against external mechanical damage and abrasion. Suitable for industrial environments with risk of impact or debris.
• Fire covers: Oversized covers with internal insulation, engineered to protect the expansion joint during short-duration flash fire events. Typically specified for firewater lines and safety-critical piping.
• Sun covers: UV-resistant covers to shield elastomeric elements from ultraviolet exposure, reducing premature aging in outdoor installations.

Typical Applications

Fire covers are commonly installed on fire water lines where the piping must remain operational during brief thermal incidents. Sun covers are selected for outdoor installations, desalination plants, pump stations, refineries, chemical plants, and external HVAC systems where UV exposure accelerates elastomer degradation.

Relation to Pipe Insulation

MACOGA advises against installing thermal insulation directly over elastomeric expansion joints where possible. Full insulation coverage can restrict visual inspection, trap moisture, and conceal damage, cracks, or deformation of the elastomer body.

Inspection and Maintenance

Covers must allow access for periodic inspection. Routine checks should assess external wear, surface changes, leaks, deformation, corrosion of metallic parts, and correct tie rod positioning. MACOGA recommends inspection one week after commissioning and subsequently every 12 months.

FAQ

Do covers protect against pressure thrust?
No. Covers are external protective accessories. Pressure thrust must be managed with anchors, tie rods, hinged/gimbal, or pressure balanced configurations.

Do covers include actuators?
No. Covers are passive protective components, selected based on installation environment, thermal hazard, UV exposure, and maintenance access requirements.