The 98H and 98HH Series are direct-operated, spring-loaded backpressure / relief valves. The 98H Series are used in a variety of steam backpressure / relief applications, such as power generation, heating and cooling systems, and process systems.

The Type 98HD uses additional loading pressure to maintain relief differential pressure settings. This backpressure / relief valve is used for differential control in steam applications, such as steam atomization of fuel gas for a boiler.

The 98L Series are direct-operated backpressure/relief valves that are used in a variety of liquid or gas applications, such as pump recirculation, general backpressure, and relief applications. The Type 98LD uses additional pressure loading to maintain relief differential pressures or backpressure.

• Features
• Body Sizes and End Connection Styles
• Temperature Capabilities
• Maximum Relief (Inlet) Pressures
• Relief Set or Differential Pressure Ranges
• Approximate Weights
• Additional Technical Data

Features

• Highly Versatile
• Close, Stable Regulation
• Compact, Rugged Design
• Wide Material Selection
• In-line Maintenance
• Hastelloy C and Monel Materials Available
• Chemically Compatible Elastomers
• NACE Construction Available
• Differential Pressure Capability
  

Body Sizes and End Connection Styles

98H Series

Cast Iron
1/4 (DN 6) body size NPT end connections
1/2, 3/4, 1, 1-1/2 or 2 (DN 15, 20, 25, 40 or 50) body size NPT end connections

Steel or Stainless Steel
1/4 (DN 6) body size NPT end connections
1/2, 3/4, 1, 1-1/2 or 2 (DN 15, 20, 25, 40 or 50) body size NPT, CL150 RF, CL300 RF, SWE or PN 16/25/40

Note: 1/4-inch body size is only available with threaded NPT connections. DN values are provided only to body sizes with flanged end connections. 

98L Series

Cast Iron
1/4 (6 DN) body size NPT end connections
1/2, 3/4 or 1 (DN 15, 20 or 25) body size NPT end connections

Steel, Stainless Steel, Monel or Hastelloy C
1/4 (DN 6) body size NPT end connection
1/2, 3/4, or 1 (DN 15, 20 or 25) body size NPT end connections

Temperature Capabilities

Nitrile Parts: -20 to 200°F (-29 to 93°C)

Neoprene Parts: -40 to 150°F (-40 to 66°C)

Fluoroelastomer Parts: 0 to 300°F (-18 to 149°C)

Metal Diaphragm Seat:
Cast Iron Body and Spring Case: -40 to 406°F (-40 to 208°C)
Steel Body and Spring Case: -20 to 450°F (-29 to 232°C)
Stainless STeel Body and Spring Case: -40 to 450°F (-40 to 232°C)

Maximum Relief (Inlet) Pressures

Relief Set or Differential Pressure Ranges

Approximate Weights

Type 98H:

• 1/4 and 1/2-inch (DN 6 and 15) Body: 7 lbs (3,18 kg)
• 3/4 and 1-inch (DN 20 and 25) Body: 16 lbs (7,26 kg)
• 1-1/2 and 2-inch (DN 40 and 50) Body: 55 lbs (25 kg)

Type 98L:

• 1/4-inch (DN 6) Body: 6 lbs (2,80 kg)
• 1/2-inch (DN 15) Body: 13 lbs (5,90 kg)
• 3/4 and 1-inch (DN 20 and 25) Body: 30 lbs (13,6 kg)

Additional Technical Data