The Caleffi 549508A is a SEP4 unit providing 4-in-1 hydraulic, air, dirt and magnetic separation, with 2" NPT connections. It installs between the boiler circuit and the distribution circuits in hydronic heating and chilled water systems.
Best for installations where space or budget rules out separate air, dirt and magnetic devices, and where ferrous debris protection matters.
Specifications sourced from Caleffi NA technical literature, 2025 revisions.
Key Features
Four Functions in One Body
Combines hydraulic separation, air elimination, dirt separation and magnetic capture, replacing four discrete devices and their fittings.
Magnetic Ferrous Capture
A removable magnet assembly collects ferrous debris that non-magnetic separators pass through, protecting pumps and heat exchangers.
Low-Velocity Separation Chamber
An enlarged internal chamber drops fluid velocity so entrained air rises and heavier particulate settles, both continuously removed in service.
Blowdown Drain and Air Vent
An integral brass blowdown valve clears collected sediment and an automatic air vent discharges separated air without shutting the system down.
Technical Specifications
| Connection Size | 2" |
| Connection Type | NPT |
| Connection Style | Union |
| Separation Functions | 4-in-1 hydraulic, air, dirt and magnetic separation |
| Maximum operating pressure | 150 psi |
| Medium temperature range | 32 - 212 deg F |
| Material | steel |
| Product Family | SEP4 |
| Shipping Weight | 82.0 lb (approx.) |
Documentation
Design Resources
Related Products
- Caleffi 549552A : SEP4 2" ANSI Flange
- Caleffi NA549052AM : SEP4 2" ANSI Flange ASME
- Caleffi 549508US 001 : SEP4 2"
- Caleffi 549509A : SEP4 2" NPT
Frequently Asked Questions
What does Caleffi 549508A do in a hydronic system?
Caleffi 549508A provides 4-in-1 hydraulic, air, dirt and magnetic separation. A hydraulic separator creates a low-velocity zone between the boiler circuit and the distribution circuits so each pump operates against its own loop only, removing flow interference without relying on closely spaced tees.
How is Caleffi 549508A different from a plain hydraulic separator?
It performs four jobs in one vessel: hydraulic separation, air elimination, dirt separation and magnetic capture of ferrous debris. A plain hydraulic separator performs only the first, so the other three functions would require separate devices.
What size connection does Caleffi 549508A have?
It is supplied with 2" NPT connections. Sizing should be based on system flow rate rather than pipe size alone; other sizes in the SEP4 family are listed under Related Products.
What is the warranty on Caleffi 549508A?
Caleffi covers this product under its standard two-year limited warranty against defects in material and workmanship from the date of purchase. ZOT Supply is an authorized Caleffi distributor.
- Product Family:
- SEP4
- Separation Functions:
- 4-In-1 Hydraulic, Air, Dirt And Magnetic Separation
- Connection Style:
- Union
- Connection Type:
- NPT
- Connection Size:
- 2 inch
- ASME Code Stamped:
- No
- Max Operating Pressure:
- 150 psi
- Medium Temperature Range:
- 32 - 212 deg F
- Body Material:
- steel