ANKA Combination Valve
Advantage
Features:
- Application: Oil-injected Screw Compressor
- Combination valve with a compact structure integrates air-oil separator seat, oil filter seat, minimum pressure valve, and thermostatic valve.
- Imported thermostatic element is featured of long life span, stable and reliable performance.
- Strengthened spring is not easily deformed and fatigued making minimum pressure valve a reliable opening pressure.
Model Description:
Technic Data:
| Model | Diameter (mm) | Maximun Working Pressure (Bar) | Working medium Tempreature (℃) | Working Temperature (℃) | Inlet of Lubricated Oil | Outlet of Lubricated Oil | Air-oil Separator Connector | Oil Filter Seat Connector |
| CTV-15A | 15 | 16 | -20-120 | -20-60 | G1/4 | G1/4 | M22*1.5, M24*1.5 | 3/4-16UNF, 1-12UNF |
| CTV-15T | 20 | 16 | -20-120 | -20-60 | G1/4 | G1/4 | M22*1.5, M24*1.5 | 3/4-16UNF, 1-12UNF |
| CTV-20A | 20 | 16 | -20-120 | -20-60 | G1/2 | G1/2 | M22*1.5, M24*1.5 | 3/4-16UNF, 1-12UNF |
| CTV-20B | 20 | 16 | -20-120 | -20-60 | / | / | M22*1.5, M24*1.5 | / |
| CTV-20H | 20 | 16 | -20-120 | -20-60 | / | / | M22*1.5, M24*1.5 | / |
| CTV-25A | 25 | 16 | -20-120 | -20-60 | G3/4 | G3/4 | M32*1.5, M39*1.5 | 3/4-16UNF, 1-12UNF |
| CTV-25F | 25 | 16 | -20-120 | -20-60 | / | / | M32*1.5, M39*1.5 | / |
| CTV-25H | 25 | 16 | -20-120 | -20-60 | / | / | M32*1.5, M39*1.5 | / |
| CTV-32F | 32 | 16 | -20-120 | -20-60 | / | / | M39*1.5 | / |
| CTV-40H | 40 | 16 | -20-120 | -20-60 | / | / | M32*1.5, M39*1.5 | / |
How to select the right combination valve
The combination valve sits on the outlet of the oil separator and does four jobs in one body: it carries the separator seat, the oil filter seat, the minimum pressure valve and the thermostatic valve. Choose it by the discharge line diameter and by the two thread families, because those are what decide whether it bolts onto your separator.
- Body size — CTV-15 (DN15), CTV-20 (DN20), CTV-25 (DN25), CTV-32 (DN32) and CTV-40 (DN40). Match the valve to the discharge pipe, not to the motor power: an undersized valve drops the pressure the separator needs.
- Pressure and temperature — the whole range is rated 16 bar, with a medium temperature of −20 to 120 °C and an ambient range of −20 to 60 °C.
- Oil circuit — the A and T versions have the lubricating-oil inlet and outlet (G1/4 on DN15–20, G3/4 on DN25); the B, F and H versions have no oil ports and are used where the oil circuit is external.
- Threads — the separator connector is M22×1.5 / M24×1.5 on the small bodies and M32×1.5 / M39×1.5 on the larger ones; the oil filter seat takes 3/4-16UNF or 1-12UNF. Check the separator and filter you already use before ordering.
Installation and maintenance
- Mount vertically on the separator outlet, with the minimum pressure valve pointing up — the spring chamber must be able to drain back.
- The minimum pressure valve holds roughly 4.5–5 bar in the separator, which is what keeps oil carry-over down at part load. If the machine cannot build pressure, check this valve before the separator element.
- Fit new O-rings dry, not greased, and tighten the separator connector to the torque of the separator supplier — over-tightening distorts the seat and the element then leaks oil.
- The thermostatic element bypasses oil around the cooler when the oil is cold. Do not remove it to “warm up faster”: cold oil that goes straight to the airend thickens and the machine trips on high temperature.
Combination valve FAQ
How do I know which CTV size I need?
Measure the discharge pipe and the separator thread. DN15 and DN20 cover small machines up to roughly 10 m³/min, DN25 and DN32 cover the mid range, and DN40 is used on large single-stage machines. If you are between two sizes, take the larger one — the pressure drop across an undersized valve costs more than the valve.
Can I replace an original combination valve with this one?
Yes, provided the separator thread and the oil filter thread match. Send us the separator part number and the oil filter thread (3/4-16UNF or 1-12UNF) and we will confirm the equivalent before you order.
What opens the minimum pressure valve?
A spring, set at about 4.5–5 bar. It stays closed until the separator reaches that pressure, so the oil separator works at a stable pressure and the oil is pushed through the filter. A weakened spring shows up as oil carry-over in the line.