What Is a Removable Insulation Jacket (4R Cover)? Five Things to Know Before Ordering

Even after pipe insulation is complete, valves, flanges, pumps and instruments are often left uninsulated, and heat loss continues. The solution optimised for insulating these complex-shaped fittings is the removable insulation jacket, known in Korea as a 4R cover.

1. What is an insulation jacket?

An insulation jacket is a removable, custom-made insulating cover for pipe fittings such as valves, flanges, pumps, instruments and filters. It fits perfectly to complex three-dimensional shapes that conventional insulation (glasswool or mineral wool) cannot cover, and it can be removed and refitted easily for scheduled inspections.

2. Where is it used?

• Gate valves, ball valves, butterfly valves, check valves
• Flange joints and union joints
• Centrifugal and gear pump casings
• Instrumentation (pressure gauges, flow meters, thermometers)
• Box-shaped equipment (box jackets)
• Drums and tanks (drum jackets, heating jackets)

3. Choosing the inner fill

4. Choosing the outer skin

• Canvas: general outdoor use, durable, the most widely used option
• Silicone coated cloth: where oil or chemicals are present, or waterproofing is needed
• Teflon coated cloth: where strong chemical resistance is required
• Silica cloth: extreme-temperature service above 1000°C
• Aluminum skin: long-term outdoor durability where waterproofing comes first

5. Information we need to quote

• The item name (e.g. 6-inch gate valve)
• Service temperature (normal / maximum, in °C)
• Overall dimensions (length × outside diameter in mm) — a sketch or photo is fine
• Location (indoor / outdoor)
• Whether it must be removable
• Operating environment (oil, steam, chemicals and so on)
• Required thickness (mm)