PRESSURE RELIEF VALVE DBDH 20 K1X/25V

Manufacturer: Bosch Rexroth

Material #: R900334729

Model : DBDH 20 K1X/25V

***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 DBDH 20 K1X/25V (R900334729) is a high-quality screw-in cartridge valve designed for limiting system pressure in hydraulic systems. This direct-operated pressure relief valve falls under the DBD.K product family, known for its robustness and reliability in controlling operational pressures. It features a maximum operating pressure of 315 bar and can handle a maximum flow of 25 liters per minute, making it suitable for various hydraulic applications. The valve is comprised of a sleeve, spring, and poppet with a damping piston for pressure ratings up to 315 bar or a ball for the version rated at 350 bar. The desired system pressure can be precisely set using the available adjustment options, which include a sleeve with hexagon and protective cap, rotary knob, hand wheel, or a lockable rotary knob. The spring mechanism ensures that the poppet or ball maintains its position on the seat until system pressure exceeds the set value, at which point it opens to allow fluid from channel P to flow into channel T. The DBDH 20 K1X/25V is designed with versatility in mind; it offers FKM sealing material compatibility and supports various hydraulic fluids such as HL, HLP, HLPD, HVLP, HVLPD, HETG, HEES, HFDU, and HFDR. Its construction prevents loss of the adjustment component due to gimbalmounting even when completely unloaded. If necessary adjustments are required due to changes in system pressures or desired performance outcomes. Bosch Rexroth's commitment to quality ensures that this valve operates efficiently over its entire range of pressures by dividing the range into different pressure ratings corresponding to specific springs. This approach allows users to achieve precise control over their hydraulic systems' pressures with confidence in both performance and safety.

$580.82 USD

More are expected on May 16, 2025

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Status: This product is temporarily out of stock.

Qty: Delivered as early as May 16, 2025 when ordered in

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PRESSURE RELIEF VALVE DBDH 20 K1X/25V

Unpacked Weight: 0.88 kg

As screw-in cartridge valve (cartridge) For threaded connection For subplate mounting Adjustment type for pressure adjustment, optionally:
‒ Sleeve with hexagon and protective cap
‒ Rotary knob
‒ Hand wheel
‒ Lockable rotary knob

Pressure relief valves of type DBD are direct operated seat valves. They are used for limiting a system pressure.

The valves basically consist of sleeve (1), spring (2), poppet with damping piston (3) (pressure rating 25 bar … 400 bar) or ball (4) (pressure rating 630 bar) and adjustment type (5). The system pressure can be set steplessly via the adjustment type (5). The spring (2) pushes the poppet (3) or the ball (4) onto the seat. Channel P is connected to the system. The pressure existing in the system acts on the poppet surface (or the ball). If the pressure in channel P exceeds the value set at the spring (2), the poppet (3) or the ball (4) opens against the spring (2). Now, hydraulic fluid from channel P flows into channel T. The stroke of the poppet (3) is limited by the embossing (6).

In order to achieve good pressure adjustment over the entire pressure range, the entire pressure range has been divided into 7 pressure ratings. One pressure rating corresponds to a certain spring for a maximum operating pressure that can be set by means of that spring.

Type DBDS..K1X/…

Version pressure rating 25 … 400 bar (poppet seat valve)

Type DBDH 10 K1X/…

Version pressure rating 630 bar (ball seat valve, only NG10)

Notices:

The adjustment type (5) is constructed so that it cannot be lost. Due to the gimbal-mounting, the adjustment element remains loose (movable) in the adjustment type (5) in case of complete unloading. Pressure rating “25”: If despite completely unloaded adjustment type, the minimum pressure does not settle, the adjustment element has to be “pulled back” to the stop due to the low spring and/or restoring force. For pressure adjustment / increase, the adjustment element can then be screwed in again.

Screw-in cartridge valve
Maximum operating pressure 400 bar (5800 psi)
Maximum flow 250 l/min (66 gpm)
Cavity M45x1,5

Data Sheet

Download Data Sheet

Max. pressure	400
Adjustment options	Rotary knob
Product family classification	Pressure relief valve, direct operated
Productgroup ID	9,10,11,12,13,14
Product family type	DBD.K
Ports number	2
Sealing material	FKM
Cavity	M45x1,5
Product type	DBD.K
Max. flow	250
Type of connection	Screw-in cartridge valve
Nominal flow	250
Direct - Pilot	Direct acting
Connection diagram	Mounting cavity type DBD NG20
Product family	Relief
Spool Poppet	Poppet type
Ports	G 1
Weight	0.88
Hydraulic fluid	HL,HLP,HLPD,HVLP,HVLPD,HETG,HEES,HFDU,HFDR

01	02	03	04	05		06	07	08	09	10
DBD				1X	/					*

01	Pressure relief valve, direct controlled								DBD
Adjustment type for pressure adjustment
02		NG6	NG8	NG10	NG15	NG20	NG25	NG30
	Sleeve with hexagon and protective cap	✔	✔	✔	✔	✔	✔	✔	S
	Rotary knob 1)	✔	✔	✔	✔	✔	–	–	H
	Hand wheel 2)	–	–	–	–	–	✔	✔	H
	Lockable rotary knob 1,3,4)	✔	✔	✔	✔	✔	–	–	A
03	Size 6 (connection G1/4)								6
	Size 8 (connection G3/8)								8
	Size 10 (connection G1/2)								10
	Size 15 (connection G3/4)								15
	Size 20 (connection G1)								20
	Size 25 (connection G1 1/4)								25
	Size 30 (connection G1 1/2)								30
Type of connection
04		NG6	NG8	NG10	NG15	NG20	NG25	NG30
	As screw-in cartridge valve (cartridge)	✔	–	✔	–	✔	–	✔	K
	For threaded connection 5)	✔	✔	✔	✔	✔	✔	✔	G
	For subplate mounting	✔	–	✔	–	✔	–	✔	P
05	Component series 10 ... 1Z (10 ... 1Z: unchanged installation and connection dimensions)								1X
Pressure rating 6)
06		NG6	NG8	NG10	NG15	NG20	NG25	NG30
	Set pressure up to 25 bar	✔	✔	✔	✔	✔	✔	✔	25
	Set pressure up to 50 bar	✔	✔	✔	✔	✔	✔	✔	50
	Set pressure up to 100 bar	✔	✔	✔	✔	✔	✔	✔	100
	Set pressure up to 200 bar	✔	✔	✔	✔	✔	✔	✔	200
	Set pressure up to 315 bar	✔	✔	✔	✔	✔	✔	✔	315
	Set pressure up to 400 bar	✔	✔	✔	✔	✔	–	–	400
	Set pressure up to 630 bar 7)	–	–	✔	–	–	–	–	630
Seal material
07	NBR seals								no code
	FKM seals								V
	Observe compatibility of seals with hydraulic fluid used. (Other seals upon request)
Line connection
08	Pipe thread according to ISO 228/1								no code
08	SAE thread								12
Equipment Directive
09	Without type-examination procedure								no code
09	Type-examination tested safety valve according to Pressure Equipment Directive 2014/68/EU								E
10	Further details in the plain text

1)	With size 20, only available for the pressure ratings "25", "50" or "100".
2)	Only available for the pressure ratings "25", "50" or "100".
3)	Key with material no. R900008158 is included in the scope of delivery.
4)	Not available for type-examination tested safety valves.
5)	Not available for type-examination tested safety valves of size 8, 15 and 25.
6)	When selecting the pressure rating, please observe the characteristic curves.
7)	With version "G" and "P", only available as "SO292", see "dimensions".

Type-examination tested safety valves type DBD

(Component series 1X according to the Pressure Equipment Directive 2014/68/EU)

NG	Type designation	Component marking
6	DBDS 6 K1X /▢ E	TÜV.SV. "xxx" –849.5.F.αw.p TÜV.SV. "xxx" –849.5.F.G.p
	DBDH 6 K1X /▢ E
	DBDS 6 G1X /▢ E
	DBDH 6 G1X /▢ E
	DBDS 6 P1X /▢ E
	DBDH 6 P1X /▢ E
10	DBDS 10 K1X /▢ E	TÜV.SV. "xxx" –850.6.F.αw.p. TÜV.SV. "xxx" –850.6.F.G.p. TÜV.SV. "xxx" –390.4,5.F.30.p. 1)
	DBDH 10 K1X /▢ E
	DBDS 10 G1X /▢ E
	DBDH 10 G1X /▢ E
	DBDS 10 P1X /▢ E
	DBDH 10 P1X /▢ E
20	DBDS 20 K1X /▢ E	TÜV.SV. "xxx" –361.10.F.αw.p.
	DBDH 20 K1X /▢ E
	DBDS 20 G1X /▢ E
	DBDH 20 G1X /▢ E
	DBDS 20 P1X /▢ E
	DBDH 20 P1X /▢ E
30	DBDS 30 K1X /▢ E	TÜV.SV. "xxx" –362.15.F.αw.p.
	DBDH 30 K1X /▢ E
	DBDS 30 G1X /▢ E
	DBDH 30 G1X /▢ E
	DBDS 30 P1X /▢ E
	DBDH 30 P1X /▢ E

1)	Component marking for DBD. 10.1X/...; 400 bar < p ≤ 630 bar

▢	In the type designation, the pressure is to be entered by the customer; Pressure adjustment ≥ [si]30 bar [/si][imp]435 psi[/imp] and possible in 5 bar [/si][imp]75 psi[/imp] steps.
"xxx"	Value entered at the factory

For applications outside these parameters, please consult us!

general

Size			6	8	10	15	20	25	30
Weight			See dimensions
Installation position			any
Ambient temperature range	NBR seals	°C	-30 … +80
Ambient temperature range	FKM seals	°C	-15 … +80
Minimum stability of the housing materials			Housing materials are to be selected so that there is sufficient safety for all imaginable operating conditions (e.g. with regard to pressure resistance, thread stripping strengths and tightening torques).

hydraulic

Size			6	8	10	15	20	25	30
Maximum operating pressure	Inlet	bar	400		630	400		315
	Outlet	bar	315
Maximum flow (standard valves)			See characteristic curves
Hydraulic fluid			see table
Hydraulic fluid temperature range	NBR seals	°C	-30 … +80
	FKM seals	°C	-15 … +80
Viscosity range		mm²/s	10 … 800
Maximum admissible degree of contamination of the hydraulic fluid 1)			Class 20/18/15 according to ISO 4406 (c)

1)	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.

Hydraulic fluid		Classification	Suitable sealing materials	Standards	Data sheet
Mineral oils		HL, HLP, HLPD, HVLP, HVLPD	NBR, FKM	DIN 51524	90220
Bio-degradable	Insoluble in water	HETG	NBR, FKM	ISO 15380	90221
		HEEG	FKM
	Soluble in water	HEPG	FKM	ISO 15380
Important information on hydraulic fluids: For further information and data on the use of other hydraulic fluids, please refer to the data sheets above or contact us. There may be limitations regarding the technical valve data (temperature, pressure range, life cycle, maintenance intervals, etc.). The ignition temperature of the hydraulic fluid used must be 50 K higher than the maximum surface temperature. Bio-degradable and flame-resistant: If this hydraulic fluid is used, small amounts of dissolved zinc may get into the hydraulic system.

Notice:

Hydraulic counter pressures in port T add 1:1 to the response pressure of the valve set at the adjustment type.

Example:

Pressure adjustment of the valve due to spring pretensioning (see "Product description" item 2) pspring = 200 bar Hydraulic counter pressure in port T: phydraulic = 50 bar ⇒ Response pressure = pspring + phydraulic = 250 bar

Deviating technical data: Type-examination tested safety valves type DBD

(Component series 1X, according to Pressure Equipment Directive 2014/68/EU)

general

Ambient temperature range	°C	-10 … +80

hydraulic

Set response pressure		see last figure of the component marking
Maximum counter pressure in the discharge line		See characteristic curves "Counter pressure in the discharge line”
Maximum flow		The last but one figure of the component marking attached at the safety valve is always binding. For valve types which have a variable maximum flow depending on the response pressure, the discharge coefficient is specified at this place.
Hydraulic fluid		Hydraulic fluids according to DIN 51524: Hydraulic oils HL and HLP are suitable for safety valves with NBR or FKM seals.
Hydraulic fluid temperature range		-10 … +60 °C
Viscosity range		12 … 230 mm²/s

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

Size 6

Size 8 and 10

Size 15 and 20

Size 25 and 30

Notices:

The characteristic curves apply to the pressure at the valve output p = 0 bar across the entire flow range. The characteristic curves only apply with the specified environmental and temperature conditions. It has to be noted that the development of the characteristic curve will be influenced in case of deviating boundary conditions. The characteristic curves refer to the specified pressure ratings (e.g. 200 bar ). The more the set pressure value differs from the nominal pressure rating (e.g. < 200 bar), the larger the pressure increase with increasing flow gets.

Type-examination tested safety valves type DBD

(Component series 1X, according to Pressure Equipment Directive 2014/68/EU) (dimensions in mm)

Size 6

Size 10

Size 20

Size 30

Notice:

Value pairs located in the areas of the characteristic curves with gray background can not be realized with the safety valve. The characteristic curves shown here are only valid for a counter pressure of 0 bar in the discharge line.

Counter pressure in the discharge line

Basically, the valve should be operated without counter pressure in the discharge line, if possible. With counter pressure in the discharge line, the maximum flow possible is reduced. There is a relation between the maximum counter pressure pT in the discharge line and flow qV, which can be seen from the following characteristic curves. Characteristic curves for intermediate values of the response pressure which are not listed must be determined by means of interpolation.

With a flow approaching zero, the maximum counter pressure pT is in each case 10 % of the response pressure. With increasing flow, the maximum counter pressure pT is reduced.

Interpolation of intermediate values from the diagram

At the pT axis, mark 1/10 of the value of pA. Determine the next lower and the next higher characteristic curve for this point. The point marked at pT divides the section between lower and higher characteristic curve on the pT axis with a certain percentage. At the qVmax axis, divide the section between next lower and next higher characteristic curve in the same percentage as the section at the pT axis. From the zerocrossing on the qVmax axis determined in that way, draw a straight line to the value on the pT axis marked before. Mark the system flow to be secured at the qVmax axis. Read off the maximum counter pressure for this value using the line at the pT axis drawn before.

Determination of the maximum counter pressure

Example 1 (with already existing characteristic curve):

Flow of the system / accumulator to be secured: qVmax = 115 l/min Safety valve set to: pA = 315 bar. Read off the maximum counter pressure pT of approx. 22,5 bar from the diagram (see arrows, Size 6, characteristic curve 7).

Example 2 (with interpolated characteristic curve):

Flow of the system / accumulator to be secured: qVmax = 15 l/min Safety valve set to: pA = 80 bar. Value to be marked at the axis referred to as pT: 1/10 x 80 bar = 8 bar. Read off the maximum counter pressure pT of approx. 3 bar from the diagram (see arrows, dashed characteristic curve).

Size 6

Diagram for determining the maximum counter pressure pT in the discharge line at port T of the valve dependent on the flow qVmax for valves type DBD... with different response pressures pA.Intermediate values may be determined by means of interpolation. Regarding the procedure for interpolation refer to "Interpolation of intermediate values from the diagram".

pA	Response pressure in bar
pT	Maximum counter pressure in the discharge line (port T) in bar
qVmax	Maximum flow in l/min
▢ \|	Interpolation area \|, for valves with response pressure pA = 30 ... 110 bar and maximum flow qVmax = 14 ... 27 l/min
▢ ‖	Interpolation area ‖, for valves with response pressure pA = 115 ... 400 bar and maximum flow qVmax = 52 l/min

Size 10

pA	Response pressure in bar
pT	Maximum counter pressure in the discharge line (port T) in bar
qVmax	Maximum flow in l/min
▢ ▢	Interpolation areas

Size 20

Size 30

Threaded connection "G"

(dimensions in mm)

Dimensions in mm

1.1	Adjustment type "S” (example) Grub screw with hexagon and protective cap; Internal hexagon (NG6 … NG20) External hexagon (NG25 and 30)
2	Name plate
3	4 valve mounting bores
4	Additional port (P), optional (e.g. for pressure measurement); not possible for NG10 and pressure rating > 400 bar (= version “SO292”). Dimensions see dimensions D4, tightening torque see table.

NG	B1	B2	ØD1	D2	ØD3	D4	H1	H2	L1	L2	L3	L4	L5	L6	T1	T2
NG	mm	mm	mm		mm		mm	mm	mm	mm	mm	mm	mm	mm	mm	mm
6	45	60	25	M6	6.6	G1/4	25	40	80	4	15	55	40	20	10	12
8	60	80	28	M8	9	G3/8	40	60	100	4	20	70	48	21	15	12
10	60	80	34	M8	9	G1/2	40	60	100	4	20	70	48	21	15	14
15	70	100	42	M8	9	G3/4	50	70	135	4	20	100	65	34	18	16
20	70	100	47	M8	9	G1	50	70	135	5.5	20	100	65	34	18	18
25	100	130	56	M10	11	G1 1/4	60	90	180	5.5	25	130	85	35	20	20
30	100	130	65	M10	11	G1 1/2	60	90	180	5.5	25	130	85	35	20	22

NG	Tightening torques MA in Nmfor fittings 1)		Weight, approx. in kg
NG	Plug screw (4)	Pipe fittings	Weight, approx. in kg
6	30 Nm	60 Nm	1,5 Kg
8	40 Nm	90 Nm	3,7 Kg
10	60 Nm	130 Nm	3,7 Kg
15	80 Nm	200 Nm	6,4 Kg
20	135 Nm	380 Nm	6,4 Kg
25	480 Nm	500 Nm	13,9 Kg
30	560 Nm	600 Nm	13,9 Kg

1)	The tightening torques are guidelines, referring to the maximum operating pressure and when using a manual torque wrench (tolerance ±10 %).

Screw-in cartridge valve "K"

(dimensions in mm)

Dimensions in mm

Cartridge valve

Dimensions in mm

1.1	Adjustment type "S” – Grub screw with hexagon and protective cap; internal hexagon (NG6 … NG20), external hexagon (NG30)
1.2	Adjustment type “H” – rotary knob (NG6 … NG20), hand wheel (NG30)
1.3	Adjustment type "A” – lockable rotary knob NG6 … NG10 (NG20 …100 bar)
4	Port P, at any place at the circumference or at the front side
5	Port T, at any place at the circumference
6	Type designation
7	Pressure rating (stamped in)
8	Marking (adjustment of the zero position after the valve has been screwed in; then fixing of the ring by horizontal shifting until it engages on the plug screw SW6).
9	Depth of fit
10	Lock nut, tightening torque MA = 10+5 Nm
11	Space required to remove the key
12	Minimum stability of the housing materials, see "Technical data".

1)	Maximum dimension
2)	All seal ring in sertion faces are rounded and free of burrs; tolerance for all angles ± 0.5°

Cartridge valve

NG	ØD11	ØD12	ØD13	L17	L18	L19	L20	L21	L22	L23	L24	SW1	SW2	SW3	SW4	SW5	SW6	Weight (approx.)
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	kg
6	34	60	-	72	11	83	28	20	-	-	64.5	32	30	19	6	-	30 -	0.4
8	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	- -
10	38	60	-	68	11	79	28	20	-	-	77	36	30	19	6	-	30 -	0.5
15	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	- -
20	48	60	-	65	11	77	28	20	-	-	106	46	36	19	6	-	30 -	1
25	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	-	- -
30	63	-	80	83	-	-	-	-	11	56	131	60	46	19	-	13	- -	2.2

Tightening torques MA in Nm for screw-in cartridge valves

NG	Pressure rating in bar
NG	Up to 200	Up to 400	Up to 630
6	50±5	80±5	‒
10	100±5	150±10	200±10
20	150±10	300±15	‒
30	350±20	500±30	‒
The tightening torques are guidelines with a friction coefficient μtotal = 0.12 and when using a manual torque wrench.

Mounting cavity

NG	D14	ØD15		ØD16	ØD17	ØD18		ØD19	L25	L26	L27	L28	L29	L30		L31	α1
NG		mm		mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	°
6	M28 x 1.5	25	H9 -	6	15	24.9	+ 0.15 - 0.2	12	15	19	30	36	45	56.5	± 5.5	65	15
8	-	-	- -	-	-	-	- -	-	-	-	-	-	-	-	-	-	-
10	M35 x 1.5	32	H9 -	10	18.5	31.9	+ 0.16 - 0.2	15	18	23	35	41.5	52	67.5	± 7.5	80	15
15	-	-	- -	-	-	-	- -	-	-	-	-	-	-	-	-	-	-
20	M45 x 1.5	40	H9 -	20	24	39.9	+ 0.16 - 0.2	22	21	27	45	55	70	91.5	± 8.5	110	20
25	-	-	- -	-	-	-	- -	-	-	-	-	-	-	-	-	-	-
30	M60 x 2	55	H9 -	30	38.75	54.9	+ 0.17 - 0.2	34	23	29	45	63	84	113.5	± 11.5	140	20

Subplate mounting "P"

((dimensions in mm)

Subplate mounting

Dimensions in mm

1.1	Adjustment type "S” – Grub screw with hexagon and protective cap; internal hexagon (NG6 … NG20), external hexagon (NG30)
2	Name plate
4	Additional port (P), optional (e.g. for pressure measurement); not possible for NG10 and pressure rating > 400 bar (= version “SO292”). Tightening torques see dimensional table)
15	Locking pin (only with type-examination tested safety valves)

For reasons of stability, use exclusively the following valve mounting screws (separate order):

4 hexagon socket head cap screws ISO 4762...-flZn-240h-L

(friction coefficient μtotal = 0.09 to 0.14)

NG	Dimensions	Property class	MA in Nm 1)	Material number
6	M6 x 50	10.9	12,5 Nm	R913000151
10	M8 x 70	10.9	28 Nm	R913000149
20	M8 x 90	12.9	28 Nm	R913000150
30	M10 x 110	12.9	56 Nm	R913000148

1)	For tightening, use a manual torque wrench with a tolerance ≤10 %.

NG	B1	B2	ØD3	H2	L1	L2	L3	L4	L5	L6	L18	Port P	Weight (approx.)
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm		kg
6	45	60	6.6	40	80	4	15	55	40	20	15	G1/4	1.5
10	60	80	9	60	100	4	20	70	45	21	15	G1/2	3.7
20	70	100	9	70	135	5.5	20	100	65	34	15	G3/4	6.4
30	100	130	11	90	180	5.5	25	130	85	35	15	G1 1/4	13.9

Deviating dimensions: Cartridge valve as type-examination tested safety valve type DBD

(Component series 1X, according to Pressure Equipment Directive 2014/68/EU) (dimensions in mm)

Dimensions in mm

1.2	Adjustment type “H” – rotary knob (NG6 … NG20), hand wheel (NG30)
1.4	Adjustment type "S" – hexagon with safety cap
4	Port P, at any place at the circumference or at the front side
6	Type designation
7	Pressure rating (stamped in)
10	Lock nut, tightening torque MA = 10+5 Nm

1)	Maximum dimension with lowest set response pressure
2)	The tightening torques are guidelines with a friction coefficient μtotal = 0.12 and when using a manual torque wrench.

NG	ØD11	ØD12	ØD13	L17	L18	L19	L22	L23	L24	SW1	SW2	SW3	Weight (approx.)
NG	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	mm	kg
6	34	60	-	80	11	83	-	-	64.5	32	30	19	0.4
8	-	-	-	-	-	-	-	-	-	-	-	-
10	38	60	-	76	11	79	-	-	77	36	30	19	0.5
15	-	-	-	-	-	-	-	-	-	-	-	-
20	48	60	-	73	11	77	-	-	106	46	36	19	1
25	-	-	-	-	-	-	-	-	-	-	-	-
30	63	-	80	91	-	-	11	56	131	60	46	19	2.2

Tightening torques MA in Nm for screw-in cartridge valves

NG	Pressure rating in bar
NG	Up to 200	Up to 400	Up to 630
6	50±5	80±5	‒
10	100±5	150±10	200±10
20	150±10	300±15	‒
30	350±20	500±30	‒
The tightening torques are guidelines with a friction coefficient μtotal = 0.12 and when using a manual torque wrench.

Sheet cut-out for front panel mounting with type-examination tested safety valves type DBD

(Component series 1X, according to Pressure Equipment Directive 2014/68/EU) (dimensions in mm)

Notice:

With valves type DBDH.K..1X/..E, the hand wheel must be removed and reassembled before the front panel assembly of the screw-in cartridge valve.

Threaded connection

Dimensions in mm

NG	B1	B2	H1	H2	ØD1		ØD2		R1
NG	mm	mm	mm	mm	mm		mm		mm
6	45	12.5	25	22.5	7	H13	40	H13	8
8
10	60	20.5	40	20.5	9	H13	44	H13	8
15
20	70	24	50	24	9	H13	55	H13	8
25
30	100	29.5	60	29.5	11	H13	73	H13	8

	2) The tightening torques are guidelines with a friction coefficientμtotal = 0.12 and when using a manual torque wrench.
	1) Component series 1X, according to Pressure Equipment Directive97/23/EC
	1) As replacement, you can also use specified screws according to DIN 912.
	2) For tightening, use a manual torque wrench with a tolerance ≤10 %.

Type-examination tested safety valves type DBD

(Component series 1X according to the Pressure Equipment Directive 2014/68/EU)

The functionality of these valves corresponds to that of the standard series (see "Product description"). Valves of type DBD..1X/..E are, however, type-examination tested pressure relief valves according to the Pressure Equipment Directive 2014/68/EU and intended for use as safety valves.

At the factory, the response pressure is set to a fixed maximum value using the adjustment type. Afterwards, the safety valve is sealed and/or secured using a safety cap which cannot be disassembled in non-destructive manner.

The safety valves are available with graded response pressures (in 5 bar steps). The valve version provided with a safety cap can no longer be adjusted. With valve versions equipped with rotary knob or hand wheel, the valve spring can be unloaded by the user and a response pressure lower than the factory setting can be set without the need of removing the lead seal.

Safety instructions

Before ordering a type-examination tested safety valve, it must be observed that for the desired response pressure p, the maximum admissible flowqVmax of the safety valve must be larger than the maximum possible flow of the system/accumulator to be secured. According to the Pressure Equipment Directive 2014/68/EU, the increase in the system pressure due to the flow must not exceed 10 % of the set response pressure (see component marking - ordering code, type-examination tested safety valves). The maximum admissible flow qVmax stated in the component marking must not be exceeded. Discharge lines of safety valves must end in a risk-free manner. The accumulation of fluids in the discharge system must not be possible (see data sheet AD2000 A2).

It is imperative to observe the application notes!

In the plant, the response pressure specified in the component marking is set at a flow of 2 l/min. The maximum flow stated in the component marking applies for applications without counter pressure in the discharge line (port T). By removing the lead seal at the safety valve, the approval according to the Pressure Equipment Directive becomes void! Basically, the requirements of the Pressure Equipment Directive and of data sheet AD2000 A2 have to be observed! It is recommended to secure type-examination tested safety valves against inadmissible disassembly by means of wiring and sealing with the housing/block (bore available in the adjustment type).

Notice:

The system pressure increases by the counter pressure in the discharge line (port T) due to the increasing flow. (Observe the data sheet AD 2000 A 2, point 6.3!)

To ensure that this increase in system pressure caused by the flow does not exceed the value of 10% of the set response pressure, the admissible flow has to be reduced dependent on the counter pressure in the discharge line (port T) (see diagrams - Safety instructions, Type-examination tested safety valves).

PRESSURE RELIEF VALVE DBDH 20 K1X/25V

Manufacturer: Bosch Rexroth

Material #: R900334729

Model : DBDH 20 K1X/25V

More are expected on May 16, 2025

This product is eligible for factory repair.

Type DBDS..K1X/…

Type DBDH 10 K1X/…

Type-examination tested safety valves type DBD

general

hydraulic

Deviating technical data: Type-examination tested safety valves type DBD

general

hydraulic

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

Size 6

Size 8 and 10

Size 15 and 20

Size 25 and 30

Type-examination tested safety valves type DBD

Size 6

Size 10

Size 20

Size 30

Counter pressure in the discharge line

Size 6

Size 10

Size 20

Size 30

Threaded connection "G"

Screw-in cartridge valve "K"

Cartridge valve

Cartridge valve

Tightening torques MA in Nm for screw-in cartridge valves

Mounting cavity

Subplate mounting "P"

Subplate mounting

Deviating dimensions: Cartridge valve as type-examination tested safety valve type DBD

Tightening torques MA in Nm for screw-in cartridge valves

Sheet cut-out for front panel mounting with type-examination tested safety valves type DBD

Threaded connection

Type-examination tested safety valves type DBD

Safety instructions

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