EMD-31 – Compact Teflon Bellows Seal for Pumps
EMD-31 – Compact Teflon Bellows Seal for Pumps
Overview
HydroMax Seal EMD-31 | Multi-Spring Teflon Bellows Component Seal (2-Slot Design)
The EMD-31 is a multi-spring, external component seal with a 2-slot replaceable Teflon bellows, engineered for parallel shaft applications. This design features a collet clamp drive mechanism and eliminates the need for elastomers, making it well-suited for chemically aggressive and high-purity environments.
Constructed with a composite glass-filled Teflon (GFT) bellows and a monolithic seal face, the EMD-31 ensures stable sealing performance under moderate pressure and temperature conditions. The seal is supplied with a stationary seat as standard.
Product Description
Design Features
- External seal configuration for parallel shafts
- 2-slot replaceable Teflon bellows – no elastomers, excellent chemical resistance
- Multi-spring design for uniform face loading
- Collet clamp driven for secure installation
- Includes monolithic seal face and stationary seat
- Suitable for larger shaft applications and aggressive media
Technical Specifications
| Seal Shaft Sizes | 1.57″ – 5.51″ |
| Inboard Seal Face Combinations | GFT/Cer GFT/SiC |
| Bellows Material | Composite GFT (Glass Filled Teflon) |
| Pressures | Up to 5 Barg (73 psig) – Shaft Size Specific |
| Temperatures | Up to 230°F |
HydroMax Seal provides a comprehensive selection of Teflon and metal bellows mechanical seals in various designs and face combinations for high-performance sealing in demanding applications.
Typical Applications & Industry Use Cases
Industries Served
Chemical processing and petrochemical systems
Water and wastewater treatment
Pharmaceutical and biotechnology production
High-purity and corrosive fluid handling services
Food and beverage manufacturing
General industrial pumping applications
Equipment & Use-Case Scenarios
- External component sealing on parallel-shaft pumps and rotating equipment
- Services with highly corrosive or aggressive chemicals
- Applications requiring elastomer-free sealing solutions to prevent degradation
- Installations where long-term seal life and chemical compatibility are critical
Why It Fits These Applications
- Composite Teflon bellows: Provides excellent chemical resistance and flexibility without the use of elastomer secondary seals, improving durability in aggressive media
- Multi-spring configuration: Ensures even loading across the bellows and seal faces for stable performance under varied operating conditions
- Collet clamp drive: Offers secure mechanical engagement and positive drive to the shaft
- Monolithic seal face: Enhances stability, wear resistance, and reliability in moderate temperature services
- Supplied stationary seat: Provides a ready-to-install configuration for typical seal chamber conditions
Installation Guidelines
Pre-Installation Preparation
Thoroughly clean the equipment shaft, seal chamber bore, and gland surfaces. Remove any corrosion, debris, or surface imperfections to ensure a smooth, sealed contact surface and proper alignment.
Seal Installation
Position the EMD-31 seal assembly onto the shaft for external configuration. Ensure the Teflon bellows, collet clamp, and stationary seat are correctly oriented. Secure the clamp drive with appropriate torque to ensure reliable mechanical engagement.
Orientation & Alignment
Verify that the seal is aligned with the shaft centerline and the fluid flow direction to avoid uneven loading, premature wear, or misalignment.
Startup Procedure
Once installed, introduce process fluid and bring the system up to operating conditions gradually. Monitor for leakage and stable operation before placing the equipment into full duty.
Maintenance & Inspection Best Practices
- Routine Visual Checks: Inspect the seal area for signs of fluid leakage, vibration, or abnormal heat
- Seal Face and Bellows Inspection: During scheduled maintenance, check seal face condition, bellows flexibility, and the stationary seat condition for wear or deposits
- Bellows Integrity: Evaluate the Teflon bellows for signs of fatigue, cracking, or deformation
- Operating Logs: Maintain records of pressures, temperatures, speeds, and fluid characteristics to support performance tracking and maintenance planning
- Spare Parts Inventory: Maintain spare stationary seats, bellows units, and seal face sets to minimize service downtime
Service & Support Options
- Application Review: Confirm that bellows material and face combinations match the fluid chemistry, temperatures, and pressures of your service environment
- Installation Assistance: Technical support can help ensure correct orientation and secure clamp engagement for reliable performance
- Preventive Maintenance Planning: Establish inspection and replacement intervals based on operating history and duty cycles
- Upgrades for Challenging Conditions: If operating demands increase (such as higher temperatures, pressures, or more aggressive chemicals), consult for alternate face materials or enhanced bellows designs to maintain reliability
Related Products
Contact HydroMax Seal
Contact HydroMax Seal today for innovative solutions, expert guidance, and over a century of engineering excellence. Your journey to mechanical sealing excellence starts with HydroMax Seal!
E-Mail: sales@hydromaxseal.com
Address: 18511 Beaumont Hwy Building D
Houston, TX
77049



