Armstrong CVW40 series wafer lift check valves are designed to effectively prevent the backflow of media in pipelines. They are suitable for non-corrosive fluids such as hot water, condensate, and oil. Compared to traditional swing or lift check valves, the CVW40 series is compact, lightweight, and easy to install. The stainless steel body ensures a long service life and high reliability.

Installation Centering

The "cam" design on the valve body makes it easy to install. By rotating the valve body so that the "cam" contacts the flange connection bolts, you can ensure the valve is perfectly centered in the pipeline.

Working Principle

The wafer lift check valve is an automatic valve that opens by the pressure of the medium. When the medium flow stops, the valve is closed by the force of the spring before reverse flow can occur.

Open

Closed

Materials

Component	Material
Body	Stainless Steel ASTM A351 CF8
Disc	Stainless Steel ASTM A351 CF8
Cover	Stainless Steel ASTM A351 CF8
Spring	304 Stainless Steel

Operating Conditions

• Design Pressure: 4.0 MPa (PN40)
• Max Operating Pressure: 4.0 MPa
• Max Operating Temperature: 425°C
• Min Operating Temperature: -25°C
• Shell Test Pressure: 6.0 MPa

Installation Instructions

1. Determine the correct installation conditions and fluid flow direction.
2. The wafer check valve is installed between two pipe flanges. It can be installed between flanges with RF and FF sealing faces, suitable for pressure ratings up to PN40.
3. Use standard gaskets and long bolts or studs (not included with the valve). Tighten the flange bolts in a diagonal sequence.
4. The CVW40 check valve can be installed in any plane. Ensure the medium flow direction matches the arrow on the valve body.
5. For valves without a spring installed on vertical pipes, ensure the flow direction is from bottom to top.

Application Limit

The check valve is not suitable for applications with severe pulsation, such as near a compressor.

Minimum Opening Pressure

During operation, the system pressure must not be less than the minimum opening pressure (kPa, 1 kPa = 101.93 mm H2O).

Flow Direction	DN15	DN20	DN25	DN32	DN40	DN50	DN65	DN80	DN100
Up	8.26	6.16	4.01	5.19	4.05	2.19	3.65	2.25	2.23
Horizontal	6.85	4.98	3.02	4.25	3.02	1.50	2.80	1.43	1.28
Down	5.44	3.80	2.01	3.31	1.99	0.83	1.91	0.61	0.32

Dimensions and Weights

Nominal Diameter	A (mm)	B (mm)	C (mm)	D (mm)	Weight (kg)
DN15	61	30	42	15	0.2
DN20	78	30	52	20	0.33
DN25	78	30	66	25	0.44
DN32	91	35	76	32	0.7
DN40	103	35	86	40	0.76
DN50	119	40	99	50	1.0
DN65	154	50	125	65	2.1
DN80	158	60	134	80	2.4
DN100	189	75	160	100	4.3

Maintenance and Troubleshooting

Valves should be stored in a dry, ventilated room. For long-term storage, check regularly, paying special attention to the cleanliness of the sealing surfaces to prevent damage.

Safety Warning

Before maintenance, confirm that the system pressure has dropped to zero (gauge pressure) and wait until the product temperature drops to room temperature. Ensure the medium in the pipeline has been blocked to prevent injury from leakage.

Spring Replacement Steps

1. Remove the valve from the pipeline and place it flat with the cover facing up.
2. Unscrew the valve cover steadily and remove the spring to be replaced.
3. Insert the new spring vertically, placing it over the disc shaft.
4. Tighten the valve cover.

Troubleshooting

Potential Fault	Cause	Solution
Sealing surface leakage	Dirt attached to the sealing surface	Clean the dirt
	Sealing surface damaged	Grind or replace
Not closing tightly	Dirt stuck in spring clearance causing failure	Clean the dirt
	Spring fatigue or damage	Replace the spring