Rexroth Check Valve: Cartridge vs Sandwich Options | Nabor

A Rexroth check valve is often described as a simple one-way component, but sourcing becomes more specific once mounting, cracking pressure, flow direction and leakage expectations are considered. Cartridge and sandwich designs can perform similar one-way functions while fitting very different manifold architectures.

For a replacement inquiry, the first question is not “Which check valve has the same size?” It is “How is the existing valve integrated into the circuit, and what must be blocked or allowed in each direction?”

Cartridge check valves: compact function inside the manifold

Cartridge check valves are installed in a machined cavity or block. They are useful where designers want a compact manifold and do not need a separate sandwich plate between stack-mounted valves.

Nabor’s current model list includes R900344919 M-SR 30 KE05-1X/, an M-SR cartridge check valve reference. It also includes R900345372 M-SR15KE05-1X/ and R900340979 M-SR20KE05-1X/. Published M-SR data shows that size, angle/straight-through architecture and cracking-pressure code are separate configuration fields, so the full type code matters.

Sandwich check valves: add the function to a valve stack

A sandwich check valve is installed between a directional valve and subplate/manifold. It can add one-way blocking without redesigning the whole manifold block, but the controlled port and mounting pattern must be correct.

The updated list includes R901086081 Z1S 6 C05-4X/V. This is a Z1S Size 6 sandwich check-valve reference. Before ordering, confirm which port path is checked, the cracking-pressure code, seal material and the mounting pattern used by the existing valve stack.

Cracking pressure is a functional parameter, not a small detail

The spring or cracking-pressure option determines how much differential pressure is needed before the valve opens in the permitted direction. A lower value may suit a low-loss return path, while a higher value can be used where the circuit needs a deliberate pressure threshold. The correct choice depends on the actual circuit, not on a generic preference for “low pressure drop.”

For M-SR families, published options can include different cracking-pressure codes. This is one reason a partial model such as “M-SR15” is not enough for a repeat order.

Check these items before comparing cartridge and sandwich options

· Flow direction that must be allowed and blocked

· Required cracking pressure

· Normal and maximum flow

· Maximum operating pressure

· Cavity or sandwich mounting interface

· Seal material and hydraulic fluid

· Whether pilot opening is required instead of a simple non-return function

· Available stack height and mounting-screw length for sandwich installations

The mounting interface should be checked against the relevant standard or manufacturer drawing. ISO 4401 mounting surfaces are commonly used for subplate and sandwich valve interfaces, but the exact port pattern and size still need to match the installed system.

Current Nabor check-valve references

RFQ checklist for a Rexroth check valve

FAQ

Is a cartridge check valve interchangeable with a sandwich check valve?

No. They use different installation architectures. The circuit function may be similar, but the manifold or valve stack must be designed for the correct form.

Why does cracking pressure matter?

It determines the pressure differential required before the permitted flow path opens, which can influence return pressure and actuator behavior.

Can I identify a check valve from its outside dimensions?

Not reliably. The internal flow path, cracking-pressure code, cavity or sandwich interface and seal version may differ.

What if the circuit needs reverse flow on command?

That may require a pilot-operated check valve rather than a simple non-return valve. The pilot source and drain conditions should then be included in the RFQ.

Choose the architecture before comparing price

For a Rexroth check valve inquiry, identify whether the machine uses a cartridge cavity, a sandwich stack or another mounting arrangement. Then confirm flow direction, cracking pressure and operating conditions. That keeps sourcing focused on the actual circuit rather than a visual match.

Reference: Nabor R900344919 M-SR 30 KE05-1X/ product page

Reference: M-SR15KE05-1X/ technical listing