DA20-2-5X/315-10/12

Manufacturer: Bosch Rexroth

Material #: R978902561

Model : DA20-2-5X/315-10/12

***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Bosch Rexroth directly.***
The Bosch Rexroth DA20-2-5X/315-10/12 (R978902561) is a pilot-operated pressure cutoff valve that plays a crucial role in hydraulic accumulator charging circuits. Its primary function is to fill an accumulator until a preset charging pressure is achieved, at which point it switches the flow to depressurized circulation until the system's pressure drops by a specified switching pressure differential, before initiating the charging process once again. This valve features a main housing, pilot control valve, main spool insert, and check valve. It operates by directing pump flow through different channels: from P to B and P to T during normal operation and from P to T and P to A when switching occurs. The control of this flow depends on the pressure levels in the system and the settings of the screwin cartridge valve. The DA20-2-5X/315-10/12 boasts an adjustable switching pressure differential, allowing for fine-tuning to match specific system requirements. Adjustments are secured with a clamping screw and lock nut to maintain consistent operation. It also includes features like shock damping through its nozzle design in certain versions (FSB), enhancing stability during operation. In terms of construction, this model offers flexibility with various adjustment types such as rotary knobs or spindle adjustments with protective caps for subplate mounting configurations. Additionally, it can be equipped with solenoid-operated unloading via a builton directional spool valve for added control versatility. The Bosch Rexroth DA20 series valves are designed for maximum operating pressures and flows, ensuring they can handle demanding hydraulic applications effectively. Users must select appropriate connections and check valves that meet or exceed specified flow characteristics for optimal performance within their hydraulic systems.

$2,322.00 USD

More are expected on November 22, 2024

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Status: This product is temporarily out of stock.

Qty: Delivered as early as November 22, 2024 when ordered in

This product is eligible for factory repair.

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For subplate mounting As cartridge valve 4 adjustment types, optionally:
• Rotary knob
• Adjustment spindle with protective cap
• Lockable rotary knob with scale
• Rotary knob with scale 4 pressure ratings Solenoid-operated unloading via built-on directional spool valve

Type DA…FS… (freely adjustable switching pressure differential)

The pressure valve type DA is a pilot-operated pressure cut-off valve. For example, it is used in accumulator charging circuits. Here, an accumulator is filled until the accumulator charging pressure is reached. After reaching the accumulator pressure, the valve switches the flow to depressurized circulation until the pressure in the hydraulic system has fallen by the switching pressure differential. Afterwards, the charging process is started again.

The pressure cut-off valve generally consists of main housing (1), pilot control valve (2 and 3), main spool insert (4) and check valve (7).

Switching of the pump flow from P to B to P to T.

The pump delivers via the check valve (7) into the hydraulic system (P to A). The pressure applied in channel A acts via the control line (8) on the control spool in the pilot control valve (3). Simultaneously, the pressure in channel P is applied via nozzle (5) to the spring-loaded side of the main spool (4) and via the control line (9) and at the inlet (11) of the screw-in cartridge valve (3). As soon as the top cut-off pressure set at the screw-in cartridge valve (3) by means of the adjustment spindle (12) is reached in the hydraulic system, the screw-in cartridge valve opens the connection from the spring-loaded side of the main spool (4) to the return line (10) to T internally (type DA ...) or externally via port Y (type DA ...Y).

Due to the nozzle (5), a pressure drop occurs at the main spool (4). It is lifted from the seat and opens connection P to T. The check valve (7) closes the connection from P to A. The actuator pressure A holds the screw-in cartridge valve (3) in open position.

Switching of the pump flow from P to T to P to A.

If the actuator pressure A has fallen to the pressure value set at the adjustment spindle (14), the screw-in cartridge valve (3) switches to initial position and closes the connection from the spring-loaded side of the main spool (4) to the return line (10). This way, the pressure on the spring-loaded side of the main spool (4) is increased and the connection from P to T is closed by the compression spring (6). The pump again delivers via the check valve (7) into the hydraulic system from P to A.

Version "FSB07"

The nozzle of this valve is located in the control line (11) for potential switching shock damping. This way, the circulation pressure (P to T) is increased. See characteristic curves.

Type DA 10 -2-5X/.FS…

Notices!

Only indirect pressure limiting function:

A pressure limiting function of the pump pressure (to the tank) is not directly provided but only indirectly via the check valve (7), control line (8) and pilot control valve (2) to channel T.

Setting the switching pressure differential

At the factory, the valves are set at nominal pressure to a switching pressure differential of approx. 10 % to 12 %. A setting of 50 % of the nominal pressure is possible.

On delivery, the adjustment spindle (12) is screwed out and set to the minimum adjustable switching pressure.

By screwing in the adjustment spindle (12), the top switching pressure may be increased.

The switching pressure differential is adjusted via the adjustment spindle (14): Screw out to reduce, screw in to increase.

The pressure adjustments are secured via the clamping screw (13) and lock nut (15).

Different system conditions (particularly high pump and actuator flows) may lead to higher switching pressures than indicated in the characteristic curves. Here, the valve offers the possibility of optional adjustment of the switching pressure differential to the system.

Type DA… (fixed switching pressure differential 10 % or 17 %)

The function of this valve complies with the function of version "FS". At the pilot control valve, however, only the top switching pressure and not the switching pressure differential can be set.

The pilot spool surface (16) exceeds the effective ball (17) surface optionally by 10 % or 17 %.

This way, the effective force at the pilot spool (16) exceeds the effective force at the ball (17) by 10 % or 17%.

Switching of the pump flow from P to B to P to T.

The pressure in channel P is applied via nozzles (5) and (9) to the spring-loaded side of the main spool (4) and at ball (17) in the pilot control valve (2). As soon as the cut-off pressure set at the adjustment spindle (12) is reached in the hydraulic system, the ball (17) opens against the spring (18). The hydraulic fluid now flows via nozzles (5) and (9) into the spring chamber (19) to the return line (10) to T (type DA ...) or externally via port Y (type DA ...Y). The main spool (4) is lifted from the seat and opens connection P to T. The check valve (7) closes the connection from P to A. Via the pilot spool (16), the actuator pressure A holds the ball in the pilot control valve (2) in open position.

Switching of the pump flow from P to T to P to A.

If the actuator pressure A drops by the switching pressure differential range of 10 % or 17 % in comparison with the set cut-off pressure (according to characteristic curves on page 11), the spring (18) closes the ball (17) in the pilot control valve (2). This way, the pressure on the spring-loaded side of the main spool (4) is increased and the connection from P to T is closed by the compression spring (6). The pump again delivers via the check valve (7) into the hydraulic system from P to A.

Type DA 10 -1-5X/…

Type DAC…

Pressure cut-off valve type DAC 30 …FS…

This valve consists of pilot control housing (2), screw-in cartridge valve (3) as pilot control element and a main spool insert (4).

Pressure cut-off valve type DAC …10/17...

This valve consists of pilot control valve (2) and an optional main spool insert (4).

Information for circuit design with type DAC...

The ports required for actuator (A), pump (P) and tank (T), the required control lines (8) and (10) as well as the required check valve (7) are not included in the scope of delivery. These have to be selected according to the applicable size and the flow. Connections require sufficient cross-section and blocking has to be prevented by appropriate design and layout. Between actuator (A) and pump (P), a sufficiently dimensioned check valve with flow characteristics in compliance with or exceeding the characteristic curves specified on page 12 has to be applied.

01	02	03	04	05		06		07		08		09	10	11	12		13	14	15	16	17	18
DA					–		–	5X	/		–					–						*

01	Pressure cut-off valve	DA
02	without directional spool valve	no code
03	Valve complete (subplate mounting)	no code
	Pilot control valve without main spool insert (cartridge valve) (do not enter nominal size)	C 1)
	Pilot control valve with main spool insert (cartridge valve) (enter valve size 30)	C
04	Size 10	10
	Size 25	20
	Size 32	30
Adjustment types
06	Rotary knob	1
	Adjustment spindle with protective cap	2
	Lockable rotary knob with scale	3 2)
	Rotary knob with scale	7
07	Component series 50 … 59 (50 … 59: unchanged installation and connection dimensions)	5X
Pressure adjustment range
08	25 to 50 bar	50
	50 to 100 bar	100
	100 to 200 bar	200
	200 to 315 bar	315
Switching pressure differential (P → A)
09	on average 10 %	10
	on average 17 %	17
	freely adjustable switching pressure differential (see characteristic curves)	FS 4)
Damping nozzle
10	without nozzle	no code
10	Nozzle Ø 0.7 mm (see characteristic curves)	B07 6)
11	Pilot oil return, internal	no code
11	Pilot oil return, external	Y
12	without directional spool valve	no code
13	Direct voltage 24 V	G24 1)
13	Alternating voltage 230 V, 50/60 Hz	W230 1)
14	With concealed manual override	N9 1)
	With manual override	N 1)
	Without manual override	no code
Electrical connection
15	without mating connector, individual connection with connector according to DIN EN 175301-803	K4 1; 3)
Seal material
16	NBR seals	no code
	FKM seals (other seals upon request)	V
	Observe compatibility of seals with hydraulic fluid used.
17	Further details in the plain text	*

	1) Only versions "10" and "17".
	2) H-key with material no. R900008158 is included in the scope of delivery.
	3) Mating connectors, separate order.
	4) Only with version "2".
	5) With nozzle: Switching shock damping leads to increased circulation pressure (P → T)
	Without nozzle: Undamped leads to reduced circulation pressure (P → T) (see characteristic curves)
	6) Only with version "FS"

Preferred types and standard units are specified in the EPS (standard price list).

general

Size			10	25	32
Weight	Type DA	kg	3.8	7.7	13.5
	Type DA …FS	kg	4.4	8.3	14.1
	Type DAC …	kg	1.2
	Type DAC 30…	kg	1.4
	Type DAC 30…FS	kg	1.9
Installation position			any
Ambient temperature range	NBR seals	°C	-30 … +80
Ambient temperature range	FKM seals	°C	-20 … +80

hydraulic

Size			10	25	32
Maximum operating pressure	Port P	bar	315
	Anschluss A 1)	bar	315
	Port T 2) 3)	bar	100
	Port Y 2) 3)	bar	100
Set pressure range	Pressure rating 50	bar	25 … 50
	Pressure rating 100 4)	bar	50 … 100
	Pressure rating 200 4)	bar	100 … 200
	Pressure rating 315 4) 5)	bar	200 … 315
Switching pressure differential	Version "FS"		freely adjustable (10 % to 50 % of nominal set pressure)
	Version "10" 4)	%	10
	Version "17" 4)	%	17
Maximum flow	Version "FS"	l/min	120	250	400
	Version "10"	l/min	40	80	120
	Version "17"	l/min	60	120	240
Hydraulic fluid			Mineral oil (HL, HLP) according to DIN 51524, other hydraulic fluids on request
Hydraulic fluid temperature range	NBR seals	°C	-30 … +80
	FKM seals	°C	-20 … +80
Viscosity range	Maximum	mm²/s	10 … 800
	Recommended	mm²/s	20 … 60
Maximum admissible degree of contamination of the hydraulic fluid 6)			Class 20/18/15 according to ISO 4406 (c)

1)	(after switching P to T)
2)	Attention! The applied pressure adds to the set pressure! The switching pressure differential remains unchanged within the setting range!
3)	The tank pressure must not exceed the pump pressure.
4)	For switching pressure differential adjustment, the following points must be observed:The top and bottom switching points must be within the setting range of the pressure rating (e.g. for a pressure rating of 100 bar: top switching point 100 bar, bottom switching point 50 bar ≙ 50 % switching pressure differential)– The minimum switching pressure differential mainly depends on the system (set pressure, pump and actuator flow, accumulator size and preload, line length and resistance, etc.) Here, the valve offers the possibility of optional adjustment of the switching pressure differential to the system. For these reasons, however, the minimum adjustable switching pressure differential of the valve cannot always be realized at the system. – Generally: Reduce the tubing between pressure cut-off valve and hydraulic accumulator to a minimum and ensure depressurized pilot oil (Y) discharge as possible. – For the switching pressure differential factory setting, refer to the respective information sheet.
5)	Type DA …FS... 150 to 315 bar
6)	The cleanliness classes specified for the components must be adhered to in hydraulic systems. Effective filtration prevents faults and simultaneously increases the life cycle of the components. For the selection of the filters, see www.boschrexroth.com/filter.

For applications outside these parameters, please consult us!

(measured with HLP46, ϑOil = 40 ±5 °C)

Size 10

Circulation pressure dependent on flow qV P and damping (P → T)

Size 25

Circulation pressure dependent on flow qV P and damping (P → T)

Size 32

Circulation pressure dependent on flow qV P and damping (P → T)

Notice!

The flow depends on the set switching pressure differential.

Pressure rating 50 bar

Switching pressure differential (P → A) dependent on the cut-off pressure pO (type DA …)

Pressure rating 100 bar

Switching pressure differential (P → A) dependent on the cut-off pressure pO (type DA …)

Pressure rating 200 bar

Switching pressure differential (P → A) dependent on the cut-off pressure pO (type DA …)

Pressure rating 315 bar

Switching pressure differential (P → A) dependent on the cut-off pressure pO (type DA …)