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AT 4550

Safety Valve AT 4550

Full lift safety valve. Flanged connections. Nodular iron or steel. Metallic seated disc. DN20/40-200/300, PN16-40.

Dimension rangeDN 20-200
PN40
Temperature range-85°C to +450 ºC
MaterialNodular iron, Steel

Variations

Article number Amount
AT 4550

Product information

Main facts

Dimension rangePNTemperature rangeMaterial
DN 25-10040-60°C to +350 ºC Nodular iron
DN 20025-60°C to +350 ºC Nodular iron
DN 20-15040-85°C to +450 ºCSteel
DN 20025-85°C to +450 ºCSteel

Range of Application

Safety valve for steam.
Not suitable as an over-flow valve.
DN 125 and 150 are not available in nodular iron. Please choose AT 4541 with closed bonnet (see separate leaflet).

Quality Assurance

Approved by TÜV and several other classification authorities.
Fulfils the requirements according to ISO 4126.
Certificate SS-EN 10204, type 2, 3 and from most of the classification authorities.
Type of certificate has to be specified upon ordering.

CE-marking
Meets the requirements in AFS 2016:1 and 2014/68/EU (Pressure Equipment Directive) according to category IV, fluids group 1 and 2.

Material Specification

1 Body0.7043/nodular iron Gr.60-40-18 resp. 1.0619/SA 216 WCB/steel
2 Seat1.4404/316L
3 Disc1.4122/hardened stainless steel
4 Spindle1.4021/420
5 Spring 1.1200, 1.8159, 1.7102/carbon steel
5Spring (for temp>200oC)1.4310/stainless steel
6 Guide1.4104 tenifer/chrome steel tenifer
7 Bonet0.7040, 0.7043, 1.0619/nodular iron Gr.60-40-18, SA 216 WCB/steel
8 Spring plate 2 pcs1.0718/steel
9 Adjusting screw1.4104 PTFE/chrome steel PTFE
10Ball 1.3541/hardened stainless steel
11Lifting device (3) 1.0718, 0.7043/12L13 or Gr.60-40-18

Dimension and Weight

DN Inlet20253240506580100125150200
DN Outlet4040506580100125150200250300
Flow diameter182329374660749298125165
A2192343313724195296066636637981090
*A with bellows 2522733734104655996657197198561090
B95100110115120140160180200225300
C85105115140150170195220250285290
D150150200250300350400450450450700
Weight9912162232567585131285
*Weight with bellows9,41013172436608393142289
Dimensions in mm, weights in kg.
* For valves with bellows and gas tight bonnets see separate sheet AT4547, 4548

Function and Design

Spring loaded and directly acting safety valve for steam, with full lift opening characteristics.
Not suitable for liquids and gases due to the open bonnet. The function of the open bonnet is to ventilate and cool the spring from the hot steam.
With open lifting device for manual testing.
Metallic seated disc.

Technical Information

Pressure increase
The safety valve is fully open at an overpressure exceeding the set pressure with a maximum of 5 %.
For set pressure lower than 1,0 bar, the overpressure is set pressure + 0,1 bar.
If lower overpressure is requested please contact Armatec.


Blowdown

Blowdown

Blowdown

Steam:Max 10% at set pressure > 3,0 barg
Max 0,3 bar at set pressure ≤ 3,0 bar
If lower blowdown pressures are required please contact Armatec.

Pressure and temperature

AT 4550GGG (nodular iron) AT 4550 (steel)
Set pressure max. Temp. Set pressure max. Temp.
DNbar -60°C to +350°Cbar-85°C to +450°C
20 2932
25 2932
32 2932
40 2932
50 2932
65 2932
80 2932
100 29 32
125 1628
150 1617(25)
200 20(25)20(25)

Pressure and temperatures according to applied standards for each valve material.
Set pressure in paranthesis for valves with a special spring. At temperatures above 200oC the temperature has to be specified in the order, so that a high temperature spring is used.
If other temperatures and pressures limits are requested please contact Armatec.

Soft sealing

AT 4550 is a metallic seated valve.
If a soft-sealed valve is requested please see separate leaflet, AT 4542/4545/4581.

Additional information

Sizing based on submitted data can be performed on request.
Please state: Capacity/power, maximum temperature (for superheated temperature) and set pressure.
For fluids other than steam, see separate leaflet series AT 4541.
Bar implies bar gauge: bar(ö), bar(g), bar(e), atö or kg/cm2 if nothing else is stated.

Coefficient of performance steam/gas, αd D/G
0,7

Coefficient of performance liquids, αd F
0,45

Flow diameter (Do), see table Dimension and Weight.

Sizing DN20-100

DN 20 25 32 40 50 6580100
Seat18 mm 23 mm 29 mm 37 mm 46 mm 60 mm74 mm92 mm
Pset

bar

Steam Steam Steam Steam Steam SteamSteamSteam
0,2 93 152 241 393 608 103315672422
0,5 144 236 374 610 943 160024333767
1 210 342 544 887 1367 232235445478
2 336 548 870 1411 2189 372256678756
3 451 737 1167 1900 2944 5011762211778
4 563 919 1456 2378 3667 6244951114667
5 674 1100 1744 2844 4400 74891133317556
6 784 1278 2033 3311 5122 87111322220444
7 896 1456 2322 3778 5844 99441511123333
8 1006 1633 2600 4244 6567 111111688926222
9 1111 1811 2889 4711 7278 123331877829111
10 1222 2000 3178 5178 8000 135562066732000
12 1440 2356 3744 6100 9433 160002433337667
14 1656 2711 4322 7033 10867 184442811143444
16 1878 3078 4889 7967 12222 208893177849222
18 2100 3433 5456 8889 13667 233333555655000
20 2322 3789 6033 9822 15111 257783922260667
22 2544 4156 6611 10756 16556 282224300066556
24 2767 4522 7189 11667 18000 307784677872333
26 2989 4878 7767 12556 19444 332225055678222
28 3211 5244 8344 13556 21000 356675433384000
30 3433 5611 8922 14444 22444 382225811189889
32 3656 5978 9511 15444 23889 406676188995778
Pset = set pressure
According to applied standards the value above should be multiplied with the safety factor 0,9.
Saturated steam in kg/h.
Capacities are given for an overpressure of 10% of set pressure.
Contact Armatec for sizing with other fluids etc.

Sizing DN125-200

DN 125 150 200
Seat 98 mm 125 mm 165 mm
Pset
barSteamSteamSteam
0,2 2756 44787811
0,5 4278 695612111
1 6211 1011117555
2 9933 1611128111
3 13333 2166737889
4 16667 2711147222
5 19889 3244456555
6 23222 3777865889
7 26444 4311175222
8 29778 4844484444
9 33000 5377893667
10 36222 59000102889
12 42778 69667121111
14 49333 80222138889
16 55889 90889157778
18 62333 101556176667
20 68889 111111195555
22 75444 123333214444
2482111133333232222

Pset = set pressure
According to applied standards the value above should be multiplied with the safety factor 0,9.
Saturated steam in kg/h.
Capacities are given for an overpressure of 10% of set pressure.
Contact Armatec for sizing with other fluids etc.

For larger DN and/or higher capacities see separate product data sheet AT 4543-4580, DN 200-400.

Accessories and Options

Test Gag for blocking the safety valve
Lift stopper
Flanges drilled acc. to ANSI.
Back pressure compensating bellows, see separate leaflet AT 4547.
Safety valve with closed bonnet, soft sealed disc or in stainless steel please see separate leaflet series AT 4541.
Supplementary loading system, see AT4505.

Installation

ConnectionsFlanges drilled acc. to
AT 4550GGG (nodular iron)
Inlet/outletDN25-80: DIN EN 1092-1, PN40/DIN EN 1092-1, PN16
DN 100-150: DIN EN 1092-1, PN16/DIN EN 1092-1, PN16
DN 200: DIN EN 1092-1, PN25/DIN EN 1092-1, PN10
See separate installation and maintenance instruction. See separate installation and maintenance instruction.

Installation 4550

ConnectionsFlanges drilled acc. to
AT 4550 (steel)
Inlet/outletDN20-130: DIN EN 1092-1, PN40/DIN EN 1092-1, PN16
DN200: DIN EN 1092-1, PN25/DIN EN 1092-1, PN16
See separate installation instruction. The valve should be mounted with the bonnet in vertical position.

Maintenance and Spare parts

See separate installation and maintenance instruction.

Marking

Manufacturer, Armatec article number, DN, PN, CE-marking, material and arrow showing the flow direction.
TÜV approval label with manufacturer fig. no. 442 mounted on body.
Set pressure is punched on the outlet flange and on the TÜV approval label.

How to order

Metal seated safety valve with open bonnet
Example: AT 4550-3-18,0-25
AT 4550-3-18,0 -25
Fig. nr.DesignSet pressure (barg)DN
AT 4550GGG=nodular iron-3=open lifting device

V3=open lifting device and bellows

AT 4550=stål-2=cap (no lifting device)
V2=cap (no lifting device) and bellows