Value Collection ZMSCS70340 Silicone O-ring Dash 340 5-pack

Product Description

The VALUE COLLECTION ZMSCS70340 is a silicone O-ring with a round cross section, designed for static and dynamic sealing applications across HVAC, plumbing, and industrial equipment. It measures 3.375 inches inside diameter, 3.75 inches outside diameter, and 0.1875 inches (3/16 inches) thick, conforming to Dash 340 sizing. With a Shore A hardness of 70 and a working temperature range of -80 degrees F to 450 degrees F, this O-ring handles wide thermal swings and dry heat conditions that would degrade standard Buna-N seals. It is sold in a pack of 5. Licensed trades and maintenance technicians working with fluid systems, HVAC equipment, and chemical-handling assemblies are the typical installers.

This O-ring is suited for sealing flanged connections, pipe unions, valve stems, and equipment housings where exposure to heat, ozone, and weather cycling is expected. The silicone compound offers good resistance to ozone and outdoor weathering, along with limited oil resistance. It performs reliably in dry heat environments and applications involving certain chemicals and solvents. Residential and light commercial HVAC service, pool and spa equipment, and industrial plumbing assemblies represent typical use cases for this Dash 340 silicone seal.

Key Features

• Dash 340 standard sizing: 3.375 inches ID, 3.75 inches OD, 0.1875 inches thick
• Silicone compound rated from -80 degrees F to 450 degrees F continuous service
• Shore A hardness of 70 for firm compression sealing in standard grooves
• Good ozone and weather resistance for outdoor or exposed equipment
• Compatible with oils, certain chemicals, and solvents per manufacturer data
• Pack of 5 units per order

Compatibility

Designed as a Dash 340 O-ring replacement for equipment and assemblies that specify a 3.375-inch ID silicone seal. Confirm groove dimensions and compound compatibility before installation.

Installation Notes

O-ring installation should be performed by qualified HVAC technicians, plumbers, or maintenance professionals familiar with sealing systems. Depressurize and isolate the system before removing any existing seals. Inspect the seating groove for damage, debris, or corrosion before installing the new O-ring. Do not use petroleum-based lubricants with silicone O-rings unless confirmed compatible with the system fluid; use a silicone-compatible assembly lubricant where required to ease installation and prevent rolling.