Castel DF316/M12S filter drier — soldered Ø12 mm

Castel DF316/M12S is a hermetic filter drier with a Solid Core, designed to protect refrigeration and air-conditioning systems from moisture, acids and solid contaminants. ODS solder connections with a Ø12 mm diameter and a maximum working pressure of 50 bar ensure reliable operation in commercial refrigeration and air-conditioning installations using modern HFC, HFO and HC refrigerants.

Benefits and key features

• Solid Core — reliable filtration without breakdown: The monolithic desiccant block does not fragment under vibration or hydraulic shock — desiccant particles cannot enter the system, protecting the compressor and expansion valves from damage.
• Nominal capacity 250 cm³ — long service life: Large desiccant volume absorbs moisture over prolonged operation without premature replacement, reducing maintenance frequency and costs.
• PS 50 bar / 680 psi — for high-pressure refrigerants: High pressure rating (MWP 680 psi according to UL) covers R32, R410A, R452B, R454B and other low-GWP refrigerants used in modern air conditioners and heat pumps.
• ODS solder connection Ø12 mm — durable and leak-tight joint: Brazed copper joint eliminates common leaks from threaded fittings — compliant with PED 2014/68/EU and STD 207.
• Wide refrigerant compatibility — one filter for many systems: Approved for ASHRAE 34:2019 classes A1, A2L and A3, including HFCs, HFOs, HFO+HFC blends and hydrocarbons, simplifying spare parts and logistics.
• Temperature range −40°C … +150°C — from freezers to condensers: A single specification covers both low-temperature and high-temperature applications in comfort and industrial installations.

Technical data

Parameter	Value
Product code (100% molecular sieve)	DF316/M12S
Core type	Solid Core
ODS connection diameter	Ø 12 mm
Connection type	Soldered (ODS)
Nominal capacity	250 cm³
Outer diameter ØD	64 mm
Length L	161 mm
Maximum working pressure PS	50 bar
MWP (UL)	680 psi
Minimum operating temperature TS	−40°C
Maximum operating temperature TS	+150°C

Compatible refrigerants

The DF316/M12S filter drier is approved for refrigerants classified as A1, A2L and A3 according to ASHRAE 34:2019

FAQ — Most frequently asked questions

Which refrigerants are compatible with Castel DF316/M12S?

The filter is compatible with refrigerants classified A1, A2L and A3 according to ASHRAE 34:2019: HFC (R134A, R32, R404A, R407C, R410A, R507), HFO (R1234YF, R1234ZE), HFO+HFC blends (e.g. R448A, R449A, R452B, R454B, R513A) and hydrocarbon HC refrigerants (R290, R600, R600A, R1270).

What is the difference between DF316/M12S and DF216/M12S?

The DF316/M12S designation indicates a core made of 100% 3 A molecular sieve — it provides maximum water adsorption capacity with good acid neutralization. The DF216/M12S variant has a core of 80% molecular sieve + 20% alumina, offering very high acid neutralization capacity while retaining drying performance. DF316 is typically recommended for standard service applications; DF216 is used where there is an increased risk of oil acidification.

How should the ODS Ø12 mm connection be installed?

Installation is performed by brazing (silver or copper brazing) with a continuous nitrogen purge through the system — this prevents internal oxide formation and contamination of the desiccant. Flame exposure should be kept brief and away from the body of the filter.

When should the filter drier be replaced?

Replacement is recommended whenever the system is opened (compressor service, valve replacement), when moisture is detected by visual or analytical indicators, and after prolonged downtime without nitrogen purge protection.

Can the filter be used with HC refrigerants (R290, R600A)?

Yes — DF316/M12S is formally approved for use with A3 hydrocarbons listed on the product sheet: R290 (propane), R600 (butane), R600A (isobutane) and R1270 (propene). Relevant safety requirements for ventilation and ignition protection according to EN 378 and national regulations must be observed.

Note: Technical data and the list of compatible refrigerants are taken from the Castel DF316/M12S product sheet and the Castel technical brochure "Hermetic Filter Driers DF". Verify compatibility with the system design and applicable local regulations before selection.