Fig 520 High Lift Safety Valve

Features

Pipe Connections

Flanged inlet connections. Threaded female outlet connections, Rp (BSP) parallel to BS EN 10226-1. Most flange standards can be accommodated.

Testing

All valves are shell and seat tested (to confirm set pressure) before leaving the factory and all valves are supplied pre-set with a tamper proof seal. Pressure Test Certificate and Letters of Conformity available on request.

Product Extras

Available with Viton seat design
Padlock available (complies with M&E3)
Pressure setting locked and sealed
Drain plug fitted on all sizes

NABIC Fig 520 Dimensional Drawing

Dimensions & Weights

SIZE DN	Inlet	Ro BSP Outlet	ØA	B (mm)	C (mm)	D (mm)	E (mm)	RD
65	Flange	2″	40	350	152	175	64	1/4″
80	Flange	2 1/2″	50	390	166	195	76	1/4″
100	Flange	3″	65	480	205	210	90	3/8″

Materials

Ref No	Name of Part	Material
1	Thrust Washer	Brass, BS EN 12164 CW609N
2	Grubscrew	Steel
3	Test Lever	Brass, BS EN 1982 CC754S
4	Spring	Chrome Vandium Alloy Steel, BS 2803 735 A50 HS (Stainless Steel, BS 2056 302S26 Opt)
5	Label	Yellow kapton
6	Spring Cover	Bronze, BS EN 1982 CC491K
7	Piston	Brass, BS EN 12164 CW609N
8	Diaphragm	Silicon Rubber
9	Seat Seal Holder	Bronze, BS EN 1982 CC491K / Brass BS EN 12164 CW602N (DZR)
10	Seat Seal	PTFE (Viton Opt)
11	Starlock Washer	Stainless Steel
12	Body	Bronze, BS EN 1982 CC491K
13	Lever Pin	Steel
14	Lead Seal	Lead
15	Adjusting Screw	Brass, BS EN 12164 CW609N
16	Spring Plate	Brass, BS EN 12164 CW609N
17	Spindle	Brass, BS EN 12164 CW721R
18	Seat Seal Retaining Plate	Bronze, BS EN 1982 CC491K / Brass BS EN 12164 CW602N (DZR)
19	O-Ring	Viton
20	Seat	Bronze, BS EN 1982 CC491K
21	Seat O-ring	Viton
22	Drain Plug	Brass, BS EN 12164 CW609N

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Discharge

Discharge Capabilities

The discharge capacity of a safety valve must be equal to or greater than the output of the boiler or system it is protecting. To ensure that the correct method of sizing is used, reference should be made to the relevant BS specification for the design of the boiler or system. Fig 520 capacities are tabulated below to assist selection.

Fig 520 – Air Capacity – 10% Overpressure (BS EN 4126-1)Click to View +

std. litres/sec (Kdr=0.479)

Set Pressure Bar	65	80	100
1.00	488	762	1288
1.25	552	862	1457
1.50	616	962	1626
1.75	680	1062	1794
2.00	744	1161	1963
2.25	808	1261	2132
2.50	872	1361	2301
2.75	935	1461	2469
3.00	999	1561	2638
3.25	1063	1660	2807
3.50	1127	1760	2975
3.75	1191	1860	3144
4.00	1255	1960	3313
4.25	1319	2060	3481
4.50	1383	2160	3650
4.75	1447	2259	3819
5.00	1511	2359	3988
5.25	1575	2459	4156
5.50	1639	2559	4325
5.75	1702	2659	4494
6.00	1766	2758	4662
6.25	1830	2858	4831
6.50	1894	2958	5000
6.75	1958	3058	5169
7.00	2022	3158	5337
7.25	2086	3257	5506
7.50	2150	3357	5675
7.75	2214	3457	5843
8.00	2278	3557	6012
8.25	2342	3657	6181
8.50	2405	3757	6350
8.75	2469	3856	6518
9.00	2533	3956	6687
9.25	2597	4056	6856
9.50	2661	4156	7024
9.75	2725	4256	7193
10.00	2789	4355	7362
10.25	2853	4455	7530
10.50	2917	4555	7699
10.75	2981	4655	7868
11.00	3045	4755	8037
11.25	3109	4854	8205
11.50	3172	4954	8374
11.75	3236	5054	8543
12.00	3300	5154	8711
12.25	3364	5254	8880
12.50	3428	5353	9049

To convert to ft3/min multiply by 2.1.

Fig 520 – Steam Capacity – 10% Overpressure (BS6759) Click to View +

kg/hr (Kdr=0.479)

Set Pressure Bar	65	80	100
1.00	1328	2073	3504
1.25	1501	2345	3963
1.50	1675	2616	4422
1.70	1814	2834	4789
1.75	1849	2888	4881
2.00	2023	3159	5340
2.25	2197	3431	5799
2.50	2371	3702	6258
2.75	2545	3974	6717
3.00	2718	4245	7176
3.25	2892	4517	7635
3.50	3066	4788	8094
3.75	3240	5060	8553
4.00	3414	5331	9011
4.25	3588	5603	9470
4.50	3762	5874	9929
4.75	3935	6146	10388
5.00	4109	6417	10847
5.25	4283	6689	11306
5.50	4457	6960	11765
5.75	4631	7232	12224
6.00	4805	7503	12683
6.25	4979	7775	13142
6.50	5152	8046	13601
6.75	5326	8318	14060
7.00	5500	8589	14518
7.25	5674	8861	14977
7.50	5848	9132	15436
7.75	6022	9404	15895
8.00	6196	9675	16354
8.25	6369	9947	16813
8.50	6543	10218	17272
8.75	6717	10490	17731
9.00	6891	10761	18190
9.25	7065	11033	18649
9.50	7239	11304	19108
9.75	7413	11576	19567
10.00	7586	11847	20025
10.25	7760	12119	20484
10.50	7934	12391	20943
10.75	8108	12662	21402
11.00	8282	12934	21861
11.25	8456	13205	22320
11.50	8630	13477	22779
11.75	8803	13748	23238
12.00	8977	14020	23697
12.25	9151	14291	24156
12.50	9325	14563	24615

To convert to lb/hr multiply by 2.2.

Fig 520 – Water Capacity – Unvented System – 10% Overpressure (BS EN 4126-1) Click to View +

kg/min water (Kdr=0.479)

Set Pressure Bar	65	80	100
1.00	1072	1674	2829
1.25	1198	1871	3163
1.50	1313	2050	3465
1.70	1397	2182	3688
1.75	1418	2214	3742
2.00	1516	2367	4001
2.25	1608	2510	4243
2.50	1695	2646	4473
2.75	1777	2775	4691
3.00	1856	2899	4900
3.25	1932	3017	5100
3.50	2005	3131	5292
3.75	2075	3241	5478
4.00	2143	3347	5658
4.25	2209	3450	5832
4.50	2273	3550	6001
4.75	2336	3648	6165
5.00	2396	3742	6326
5.25	2456	3835	6482
5.50	2513	3925	6634
5.75	2570	4013	6783
6.00	2625	4100	6929
6.25	2679	4184	7072
6.50	2732	4267	7212
6.75	2784	4348	7350
7.00	2835	4428	7484
7.25	2886	4506	7617
7.50	2935	4583	7747
7.75	2983	4659	7875
8.00	3031	4734	8001
8.25	3078	4807	8125
8.50	3125	4879	8247
8.75	3170	4951	8368
9.00	3215	5021	8487
9.25	3259	5090	8604
9.50	3303	5158	8719
9.75	3346	5226	8833
10.00	3389	5292	8946
10.25	3431	5358	9057
10.50	3473	5423	9167
10.75	3514	5487	9275
11.00	3554	5551	9382
11.25	3595	5613	9488
11.50	3634	5676	9593
11.75	3674	5737	9697
12.00	3712	5798	9799
12.25	3751	5858	9901
12.50	3789	5917	10002

In the above tables, discharge capacities have been calculated in accordance with BS EN 4126-1 & BS 6759, using a derated coefficient of discharge (Kdr) 0.479, approved by AOTC.

Fig 520 – Hot Water Capacity – Unvented System – 10% Overpressure (BS EN 4126-1) Click to View +

Kw (Kdr=0.479)

Set Pressure Bar	65	80	100
1.00	832	1299	2196
1.25	941	1469	2484
1.50	1050	1640	2771
1.75	1159	1810	3059
2.00	1268	1980	3346
2.25	1377	2150	3634
2.50	1486	2320	3922
2.75	1595	2490	4209
3.00	1704	2660	4497
3.25	1813	2831	4784
3.50	1921	3001	5072
3.75	2030	3171	5360
4.00	2139	3341	5647
4.25	2248	3511	5935
4.50	2357	3681	6222
4.75	2466	3851	6510
5.00	2575	4022	6798
5.25	2684	4192	7085
5.50	2793	4362	7373
5.75	2902	4532	7660
6.00	3011	4702	7948
6.25	3120	4872	8235
6.50	3229	5042	8523
6.75	3338	5213	8811
7.00	3447	5383	9098
7.25	3556	5553	9386
7.50	3665	5723	9673
7.75	3774	5893	9961
8.00	3883	6063	10249
8.25	3992	6233	10536
8.50	4101	6404	10824
8.75	4209	6574	11111
9.00	4318	6744	11399
9.25	4427	6914	11687
9.50	4536	7084	11974
9.75	4645	7254	12262
10.00	4754	7424	12549
10.25	4863	7595	12837
10.50	4972	7765	13124
10.75	5081	7935	13412
11.00	5190	8105	13700
11.25	5299	8275	13987
11.50	5408	8445	14275
11.75	5517	8615	14562
12.00	5626	8786	14850
12.25	5735	8956	15138
12.50	5844	9126	15425

To convert to Btu/hr multiply by 3,400.
The capacities tabulated are for unvented (pressurised or sealed) heating systems.

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High Lift Safety Valve

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