Description
The McDonnell & Miller 551-S-HD is a make-up water feeder head mechanism designed for use with steam separators, receivers, and tanks in low-pressure steam heating systems. Rated for a maximum vessel pressure of 25 PSI, this head-only unit (Part Number 136600) is engineered to automatically maintain proper water levels, protecting boilers and steam system components from damage caused by low-water conditions.
Key Features
- Head mechanism only — designed for replacement or upgrade installations on compatible 551-S-HD bodies
- 25 PSI maximum vessel pressure rating for low-pressure steam system compatibility
- Suitable for use with steam separators, receivers, and tanks
- Automatically feeds make-up water to maintain safe operating water levels
- Heavy-duty (HD) construction for reliable, long-service performance in demanding steam system environments
- Part Number: 136600
- SKU: 551-S-HD
Applications
- Low-pressure steam heating boiler systems
- Steam separators, receivers, and storage tanks
- Commercial and industrial hydronic/steam plant installations
- Replacement head mechanism for existing 551-S-HD installations
Why Choose McDonnell & Miller
McDonnell & Miller, a brand under the Xylem family, has been a trusted name in boiler controls and steam system components for over a century. The 551-S-HD make-up water feeder reflects their commitment to quality, reliability, and safety in hydronic and steam heating applications.
