In the valve engineering process, seal selection is critical. In fact, it can mean the difference between a good design, and a great one. That’s why we’ve created this short presentation. It examines the relationship between seal choice and valve performance, and it addresses important design criteria, such as hardware surface finish and seal geometry. It also suggests some ways to avoid common sealing mistakes that can cost you time, money, and market share.

1. Sealing for Improved
Industrial Valve Performance
Karina Chavez
Global Market Manager, Industrial Products
Bal Seal Engineering
www.balseal.com

2. Slide 2
Industrial Valves
• Valve types
 Butterfly
 Control
 Ball
 Check
• Mechanical motion
 Linear
 Rotary
 Oscillating
• Widely varying industries
 Water and chemical plants, paper mills,
refineries, and other industrial facilities

3. Slide 3
Valve Environments
• Temperatures
 -320 °F (-196 °C) to 450
°F (232 °C)
• Pressures
 0 to 750+ psi (52 bar)
• Control, isolate, and
regulate flow:
 Gases: air, natural, sour,
corrosive, steam, etc.
 Liquids: hydraulic fluids,
water, low and high
viscosity, etc.
 Solids: powder, slurry, etc.

4. Slide 4
The Valve Seal: A Critical Component
 In gas systems
 Valves require a consistent
performing seal to minimize
specified leakage rate at
operating temperatures and
pressures
 In liquid systems
 Valves need a reliable seal to
prevent leakage
 In systems encountering solids
 Valves must be durable and
contain a robust seal to prevent
obstruction

5. Slide 5
• Geometry
 Lips optimized for increased sealing contact area
 Locking ring to prevent shrinkage away from
hardware and/or to stabilize seal in hardware
 Back-up ring incorporated to prevent extrusion at
high pressures
• Jacket material
 Filled PTFE materials (polymer, polyimide),
UHMWPE materials
 Chemically compatible
 Wear resistant
 Extrusion resistant (UHMWPE)
 Temperature resistant
 Low friction (PTFE)
• Spring energizer (canted coil, helical ribbon,
close-coil spring)
 Chemically compatible
 Corrosion resistant
 Heavy force
 Customizable loads
Seal Design Considerations
Thin seal lips
increase flexibility
Spring energizer
promotes even
wear, better seal
performance
Locking ring
prevents shrinkage
Example:
Low Temperature
Sealing

6. Slide 6
Factors That Impact Seal Design
• Performance conditions
 Speed
 Pressure
 Media
 Life expectancy
 Torque capacity
 Temperature limits
• Hardware conditions
 Shaft diameter, material,
surface finish, surface
hardness, tolerances
 Shaft/bore misalignment

7. Slide 7
Impact of Surface Finish On Friction
391
765
1366
2488
4735
0
1000
2000
3000
4000
5000
2.0 4.0 8.0 16.0 32.0
FrictionalForce
Grams
Surface Finish
Microinches RMS (Microinches Ra)
Frictional Force vs. Surface Finish
(1.8) (3.6) (7.2) (14.4) (28.8)

8. Slide 8
Case Study: Control Valve Seal Design
Requirements Solutions
• Reciprocating
(60mm stroke)
• 2 FPM
• 1095 cc/min
allowable leakage
• 14 to 2200 psi
pressure
• Temp ranging
from -320 °F to
-40 °F
• Bal Seal® canted coil spring + ribbon spring-energized seal
• Seal jacket made from filled UHMWPE
• Wear resistant properties, chemically inert, highly
compatible with LNG and other cryogens
• Extended heel design incorporated to manage high
pressure
• Modified lip to increase contact area and pressure at
low temps
• Bal Spring® canted coil spring + ribbon spring energizer
• Double spring energizer to ensure sealing to meet
leakage requirements
• Material selection based on media compatibility,
temperature, and force requirements

9. Slide 9
Case Study: Needle Valve Seal Design
Requirements Solutions
• Reciprocating
(10mm stroke)
• 2 FPM
• 290 to 2300 psi
pressure
• Temp ranging from
60 °F to 175 °F
• Bal Seal® spring-energized seal
• Seal jacket made from polyimide-filled PTFE
• Compatible with oil and grease, and optimized for
use with “softer” metal hardware materials, such
as stainless steel
• Custom short lip designed to maximize sealing at
various viscosities
• Extended heel design incorporated to manage
high pressure
• Bal Spring® canted coil spring energizer
• Stainless steel for media compatibility purposes
• Medium force spring to provide sealing even at
lower system pressure

10. Slide 10
Case Study: Ball Valve Seal Design
Requirements Solutions
• Rotary, quarter turn
• < 5 RPM
• 20,000 psi pressure
• Temp ranging from
20 °F to 250 °F
• Bal Seal® spring-energized seal with backup ring
• Seal jacket made from graphite fiber reinforced PTFE
• Compatible with various fluids and gases, such as
hydrogen fluid, nitrogen and sour gas
• Proposed to meet temperature range
• Thicker dynamic lip and contoured cavity for a more
robust seal
• Backup ring made from filled UHMWPE
• Prevents extrusion when operating at high pressures
• Increased abrasion resistance
• Bal Spring® canted coil spring energizer
• Hastelloy® for compatibility with media
• Configuration to meet specific valve requirements
(based on dynamic activity, temperature)
• Optimized deflection in modified cavity for improved
sealing

11. Slide 11
Case Study: Check Valve Seal Design
Requirements Solutions
• Reciprocating (0.5 in
stroke)
• ~1 FPM
• 20 to 600 psi pressure
• Temp ranging from
120 °F to 200 °F
• Bal Seal® spring-energized seal
• Seal jacket made from polyimide filled PTFE
• Well-suited to seal butane gas, and other fluids
like ethanol, propane, and isopropanol
• Exhibits low coefficient of friction, and
compatible with soft metal hardware to minimize
wear
• Bal Spring® canted coil spring energizer
• Stainless steel for compatibility purposes
• Applies consistent sealing pressure over large
tolerance range
• Cavity modified to incorporate heavier force
spring for better sealing

12. Slide 12
Case Study: Butterfly Valve Seal Design
Requirements Solutions
• Oscillating, slow
• 15 psi pressure
• Temp ranging from 0 °F
to 302 °F
• Bal Seal® spring-energized K-Series seal
• Seal jacket made from glass-filled PTFE
• Highly compatible with most gases, including
DCS and ammonia
• Provides excellent wear and extrusion
resistance, low outgassing
• Custom dynamic lip to allow proper functioning
of valve by preventing deformation caused by
escaping media particles
• Locking ring made from same material as hardware
• Offers retention to stabilize seal in valve
• Ensures same CTE rate during cycling
• Bal Spring® canted coil spring energizer
• Stainless steel for compatibility and temperature
resistance
• Heavy force spring for maximum sealing ability

13. Slide 13
Summary & Recommendations
• To eliminate costly mistakes and
delays, consider sealing requirements
as part of overall valve design
• In early design stages, collaborate
with Bal Seal Engineering to:
 Get consultative engineering advice
 Review valve hardware design
 Estimate frictional outcome, if relevant
 Perform Finite Element Analysis
 Engage in collaborative seal design
discussion
 Custom design a seal that meet all your
system/application requirements
 Determine recommended test failure
criteria
 Produce high-quality seal prototypes
 Perform in-house testing
 Scale up to full production

14. Slide 14
More Resources
sales@balseal.com www.balseal.com +949 460-2100 Design request form
Karina Chavez
Global Market Manager, Industrial
Products
Bal Seal Engineering
T: +1 949.460.2118
kchavez@balseal.com
July 20 © Copyright, Bal Seal Engineering, LLC. This document contains and/or refers to information that is PROPRIETARY to Bal Seal Engineering, LLC, and may not be reproduced, copied,
published, or distributed in any form or disclosed to a third party, in whole or in part, without the written authorization of an officer of Bal Seal Engineering, LLC. Products are the subject of issued or
pending United States and foreign patents. Products of Bal Seal Engineering, LLC and this document are PROPRIETARY and products may not be manufactured, or caused to be manufactured, by
any other party.

15. July 20 © Copyright, Bal Seal Engineering, LLC. This document contains and/or refers to information that is PROPRIETARY to Bal Seal Engineering, LLC, and may not be reproduced, copied, published, or distributed in any form or disclosed to a third party, in whole or in
part, without the written authorization of an officer of Bal Seal Engineering, LLC. Products are the subject of issued or pending United States and foreign patents. Products of Bal Seal Engineering, LLC and this document are PROPRIETARY and products may not be
manufactured, or caused to be manufactured, by any other party.