MODELS 6252/6254 SAFETY VALVES

Features

• Heavy duty high quality cast iron construction with stainless steel semi-nozzle, trim and disc.

• Bolted bonnet design for easy maintenance.

• Seats lapped to optical flatness.

• Dual control rings offer easy adjustability forprecision opening with minimum pre-open or simmer and exact blowdown control.

• Heavy duty lift lever assembly.

• All adjustments factory sealed to prevent tampering or disassembly.

• Each valve tested and inspected for pressure setting and leakage.

• Valves available National Board certified to ASME sections I, VIII and IV, and PED certified for non-hazardous gas.

GENERAL APPLICATION

Suitable for use on steam boilers and generators, pressure reducing stations, reciprocating or rotary air/gas compressors and for pressure vessels including tanks, receivers, intercoolers, oil/gas separators and lines.

TECHNICAL DATA

Connections:	FNPT or flanged
Sizes:	2”, 2½”, 3”
Temperature range:	-20° to 406°F (-29° to 208°C)
Pressure range:	10 to 250 psig (0.7 to 17.2 barg)
Code:	ASME I, IV, VIII and PED

NOTE

1. ASME code valves made from cast iron A126 may not be used in lethal or flammable service.

MODELS OVERVIEW

Model 6252: Cast iron, enclosed spring, SS trim. Codes: ASME I, VIII and PED

Model 6254: As model 6252 except certified for ASME code section IV – low pressure steam heating boilers. Set pressure 15 psig (1.0 barg) only. J through P orifice only. Codes: ASME IV and PED

PARTS AND MATERIALS

MODELS 6252 AND 6254

No.	Part Name	Material
1	Body	Cast iron, A126 CL A or B
2	Semi nozzle	SS, SA351 CF8M
3	Warn ring locking screw	Brass, B16 H02
4	Warn ring locking pin	SS, A582 TY 416
5	Guide	Bronze, B584 C84400
6	Guide locking screw	Brass, B16 H02
7	Guide locking pin	SS, A582 TY 416
8	Stem end	SS, A582 TY 416
9	Spring step	Brass, B16 H02
10	Compression screw	Brass, B16 H02
11	Lever⁶	Iron, A536 65 45 12
12	Compression screw lock nut	SS, SA479 316 SS
13	Lifting disc nut	Steel, A108 1018
14	Cap	Iron, A536 65 45 12
15	Lifting disc	SS, SA479 316 SS
16	Lever pin	Steel, A108 1018
17	Lever pin washer	Steel, A108 1018
18	Lever cotter pin	Steel, A108 1018
19	Stem	SS, A582 TY 416
20	Cap set screw	Steel, A108 1018
21	Bonnet	Cast iron, A126 CL A or B
22	Spring	Steel, A229, aluminum coated²
23	Bonnet bolt	Steel, A193-B7/194-7
24	Disc	SS, SA479 316 SS⁵
25	Warn ring	Bronze, B584-C84400³
26	Gag screw⁴	Steel, A108 1018
27	Wire seal	Lead seal, aluminum wire¹
28	Retainer nut	Brass, B16-H02
29	O-ring	EPDM
30	Drainhole	⅜” NPT

NOTES

1. Not shown on assembly.

2. SS A313-631 for ‘J’ orifice.

3. Brass B16-H02 for ‘J’ orifice.

4. Applies only to gag option. Gag screw ships with valve, not installed.

5. SS-SA351-C8FM for ‘Q’ and ‘R’ orifice.

6. J and K orifices use 1 piece lever as shown in diagram. All other orifices use 2 piece design, lever and yoke. Yoke material: iron, A536 65 45 12.

DIMENSIONS MODELS 6252 AND 6254

		Connections	ANS	standard,	in	inch	(mm)			Valve	dimensions	in	inch	(mm)			Approximate	weight
Model¹	Orifice		Inlet²			Outlet³			A			B			C		lb	(kg)
625*AJG	J	1½		(38.1) FNPT	2½		(63.5) FNPT	4¼		(108.0)	3½		(88.9)	18		(457.2)	40	(18.2)
625*FJG	J	1½		(38.1) FL	2½		(63.5) FNPT	4¼		(108.0)	3½		(88.9)	18		(457.2)	40	(18.2)
625*FJH	J	2		(50.8) FL	2½		(63.5) FNPT	4¼		(108.0)	3½		(88.9)	18		(457.2)	42	(19.1)
625*FJJ	J	2½		(63.5) FL	2½		(63.5) FNPT	4¼		(108.0)	3½		(88.9)	18		(457.2)	45	(20.5)
625*AKH	K	2		(50.8) FNPT	3		(76.2) FNPT	4⅝		(117.6)	4		(101.6)	18¼		(463.6)	43	(19.5)
625*FKH	K	2		(50.8) FL	3		(76.2) FNPT	4⅝		(117.6)	4		(101.6)	18¼		(463.6)	52	(23.6)
625*FKJ	K	2½		(63.5) FL	3		(76.2) FNPT	4⅝		(117.6)	4		(101.6)	18¼		(463.6)	52	(23.6)
625*FKK	K	3		(76.2) FL	3		(76.2) FNPT	4⅝		(117.6)	4		(101.6)	18¼		(463.6)	55	(25.0)
625*ALJ	L	2½		(63.5) FNPT	4		(101.6) FNPT	5½		(139.7)	4^13/16		(122.2)	21½		(546.1)	74	(33.6)
625*FLJ	L	2½		(63.5) FL	4		(101.6) FNPT	5½		(139.7)	4^13/16		(122.2)	21½		(546.1)	82	(37.3)
625*FLK	L	3		(76.2) FL	4		(101.6) FNPT	5½		(139.7)	4^13/16		(122.2)	21½		(546.1)	86	(39.1)
625*FLM	L	4		(101.6) FL	4		(101.6) FNPT	5½		(139.7)	4^13/16		(122.2)	21½		(546.1)	97	(44.1)
625*AMK	M	3		(76.2) FNPT	4		(101.6) FNPT	5⅝		(142.7)	5⅛		(130.0)	21^11/16		(550.9)	90	(40.9)
625*FMK	M	3		(76.2) FL	4		(101.6) FNPT	5⅝		(142.7)	5⅛		(130.0)	21^11/16		(550.9)	100	(45.5)
625*FMM	M	4		(101.6) FL	4		(101.6) FNPT	5⅝		(142.7)	5⅛		(130.0)	21^11/16		(550.9)	107	(48.6)
625*KNM	N	4		(101.6) FL	6		(152.4) FL	6¾		(171.5)	7¼		(184.2)	22½		(571.5)	197	(89.5)
625*KPM	P	4		(101.6) FL	6		(152.4) FL	6¾		(171.5)	7¼		(184.2)	25^13/16		(655.6)	197	(89.5)
625*KQP	Q	6		(152.4) FL	8		(203.2) FL	9¼		(234.9)	10		(254.0)	39⅛		(993.8)	493	(224.0)
625*KRP	R	6		(152.4) FL	8		(203.2) FL	9¼		(234.9)	10		(254.0)	39⅛		(993.8)	507	(230.0)

Dimensions are for reference only.

NOTES

1. Replace asterisk with desired model number.

2. Inlet flanges are ANSI B16. 1-250#.

3. Outlet flanges are ANSI B16. 1-125#.

Capacities for model 6252

NON-CODE¹AND ASME SECTION VIII AIR (SCFM), FLOW COEFFICIENT = 0.878

			Orifice,	are	in²
Set pressure	J	K	L	M	N	P	Q	R
(psig)	(1.414)	(2.022)	(3.138)	(3.960)	(4.774)	(7.018)	(12.155)	(17.600)
10	582	833	1292	1631	1966	2890	5005	7247
15	744	1064	1652	2084	2513	3694	6397	9263
20	858	1227	1904	2403	2897	4258	7375	10679
25	972	1390	2157	2722	3281	4823	8354	12096
30	1086	1552	2409	3040	3665	5388	9332	13512
35	1211	1731	2687	3391	4088	6009	10408	15070
40	1336	1910	2965	3741	4510	6630	11484	16628
45	1461	2089	3242	4092	4933	7252	12560	18186
50	1586	2268	3520	4442	5356	7873	13636	19744
55	1711	2447	3798	4793	5778	8494	14712	21302
60	1837	2626	4076	5143	6201	9115	15788	22860
65	1962	2805	4354	5494	6623	9737	16864	24418
70	2087	2984	4631	5845	7046	10358	17939	25976
75	2212	3163	4909	6195	7469	10979	19015	27534
80	2337	3342	5187	6546	7891	11600	20091	29092
90	2588	3700	5742	7247	8736	12843	22243	32208
100	2838	4058	6298	7948	9582	14085	24395	35324
110	3088	4416	6854	8649	10427	15328	26547	38440
120	3339	4774	7409	9350	11272	16570	28699	41555
130	3589	5132	7965	10051	12117	17813	30851	44671
140	3839	5490	8520	10752	12962	19055	33003	47787
150	4090	5848	9076	11453	13808	20298	35155	50903
160	4340	6206	9631	12154	14653	21540	37307	54019
170	4590	6564	10187	12855	15498	22783	39459	57135
180	4841	6922	10743	13557	16343	24025	41611	60251
190	5091	7280	11298	14258	17188	25268	43763	63367
200	5341	7638	11854	14959	18034	26510	45915	66483
210	5592	7996	12409	15660	18879	27753	48067	69599
220	5842	8354	12965	16361	19724	28995	50219	72715
230	6092	8712	13520	17062	20569	30238	52371	75831
240	6343	9070	14076	17763	21414	31480	54523	78947
250	6593	9428	14631	18464	22260	32723	56675	82063

NOTE

1. No code stamp or “NB” on nameplate below 15 psig set.

Capacities for model 6252 – metric units

NON-CODE¹AND ASME SECTION VIII AIR (Nm³/h), FLOW COEFFICIENT = 0.878

			Orifice,	area	cm²
Set pressure	J	K	L	M	N	P	Q	R
(barg)	(9.123)	(13.045)	(20.245)	(25.548)	(30.800)	(45.277)	(78.419)	(113.548)
1.0	1106	1582	2455	3098	3735	5490	9509	13769
1.5	1433	2049	3179	4012	4837	7110	12315	17832
2.0	1696	2425	3764	4750	5726	8418	14579	21110
2.5	1982	2835	4399	5551	6692	9838	17039	24672
3.0	2272	3249	5042	6363	7671	11276	19530	28278
3.5	2562	3663	5685	7174	8649	12714	22020	31885
4.0	2851	4077	6328	7985	9627	14152	24511	35491
4.5	3141	4492	6971	8797	10605	15590	27001	39097
5.0	3431	4906	7614	9608	11583	17028	29492	42703
5.5	3721	5320	8257	10420	12561	18466	31982	46309
6.0	4010	5735	8900	11231	13539	19904	34473	49915
6.5	4300	6149	9543	12042	14518	21342	36963	53521
7.0	4590	6563	10186	12854	15496	22780	39454	57127
7.5	4879	6977	10828	13665	16474	24217	41944	60733
8.0	5169	7392	11471	14476	17452	25655	44434	64340
8.5	5459	7806	12114	15288	18430	27093	46925	67946
9.0	5749	8220	12757	16099	19408	28531	49415	71552
9.5	6038	8635	13400	16911	20387	29969	51906	75158
10.0	6328	9049	14043	17722	21365	31407	54396	78764
10.5	6618	9463	14686	18533	22343	32845	56887	82370
11.0	6907	9877	15329	19345	23321	34283	59377	85976
11.5	7197	10292	15972	20156	24299	35721	61868	89582
12.0	7487	10706	16615	20967	25277	37159	64358	93188
12.5	7777	11120	17258	21779	26256	38597	66849	96795
13.0	8066	11535	17901	22590	27234	40035	69339	100401
13.5	8356	11949	18544	23402	28212	41473	71830	104007
14.0	8646	12363	19187	24213	29190	42911	74320	107613
14.5	8935	12778	19830	25024	30168	44349	76811	111219
15.0	9225	13192	20473	25836	31146	45786	79301	114825
15.5	9515	13606	21116	26647	32124	47224	81792	118431
16.0	9805	14020	21759	27458	33103	48662	84282	122037
17.2	10500	15015	23302	29406	35450	52113	90259	130692

NOTE

1. No code stamp or “NB” on nameplate below 1.1 barg set.

Capacities for model 6252

NON-CODE¹AND ASME SECTION VIII STEAM (lb/hr), STEAM COEFFICIENT = 0.878

			Orifice,	are	in²
Set pressure	J	K	L	M	N	P	Q	R
(psig)	(1.414)	(2.022)	(3.138)	(3.960)	(4.774)	(7.018)	(12.155)	(17.600)
10	1775	2538	3938	4970	5991	8807	15254	22087
15	2091	2990	4640	5855	7059	10377	17972	26023
20	2410	3447	5349	6751	8138	11963	20720	30002
25	2730	3904	6059	7646	9217	13550	23468	33981
30	3050	4361	6768	8541	10297	15137	26217	37961
35	3401	4864	7549	9526	11484	16882	29239	42338
40	3753	5367	8329	10511	12671	18627	32262	46715
45	4105	5870	9109	11496	13859	20373	35285	51092
50	4456	6373	9890	12480	15046	22118	38308	55469
55	4808	6875	10670	13465	16233	23863	41331	59846
60	5160	7378	11451	14450	17420	25609	44354	64223
65	5511	7881	12231	15435	18608	27354	47377	68600
70	5863	8384	13011	16420	19795	29099	50399	72977
75	6215	8887	13792	17405	20982	30845	53422	77354
80	6566	9390	14572	18389	22169	32590	56445	81731
90	7270	10395	16133	20359	24544	36081	62491	90485
100	7973	11401	17694	22329	26918	39571	68537	99239
110	8676	12407	19255	24298	29293	43062	74582	107993
120	9380	13413	20815	26268	31668	46553	80628	116747
130	10083	14418	22376	28238	34042	50043	86674	125501
140	10786	15424	23937	30207	36417	53534	92720	134255
150	11489	16430	25498	32177	38791	57025	98765	143009
160	12193	17435	27059	34147	41166	60515	104811	151763
170	12896	18441	28619	36116	43540	64006	110857	160517
180	13599	19447	30180	38086	45915	67497	116903	169271
190	14303	20453	31741	40056	48289	70987	122948	178025
200	15006	21458	33302	42025	50664	74478	128994	186779
210	15709	22464	34863	43995	53038	77969	135040	195533
220	16413	23470	36423	45965	55413	81459	141086	204287
230	17116	24475	37984	47934	57787	84950	147131	213041
240	17819	25481	39545	49904	60162	88441	153177	221795
250	18523	26487	41106	51873	62536	91931	159223	230549

NOTE

1. No code stamp or “NB” on nameplate below 15 psig set.

Capacities for model 6252 – metric units

NON-CODE¹AND ASME SECTION VIII STEAM (kg/h), STEAM COEFFICIENT = 0.878

			Orifice,	area	cm²
Set pressure	J	K	L	M	N	P	Q	R
(barg)	(9.123)	(13.045)	(20.245)	(25.548)	(30.800)	(45.277)	(78.419)	(113.548)
1.0	944	1350	2095	2644	3187	4685	8115	11750
1.5	1144	1635	2538	3203	3861	5676	9831	14235
2.0	1354	1936	3005	3792	4571	6720	11638	16852
2.5	1582	2263	3512	4431	5342	7854	13602	19696
3.0	1814	2593	4025	5079	6123	9001	15590	22574
3.5	2045	2924	4538	5727	6904	10149	17578	25453
4.0	2276	3255	5051	6375	7685	11297	19567	28332
4.5	2508	3586	5565	7022	8466	12445	21555	31210
5.0	2739	3916	6078	7670	9247	13593	23543	34089
5.5	2970	4247	6591	8318	10028	14741	25531	36961
6.0	3201	4578	7104	8965	10808	15889	27519	39846
6.5	3433	4909	7618	9613	11589	17037	29507	42725
7.0	3664	5239	8131	10261	12370	18185	31495	45604
7.5	3895	5570	8644	10909	13151	19332	33483	48483
8.0	4127	5901	9157	11556	13932	20480	35471	51361
8.5	4358	6231	9671	12204	14713	21628	37459	54240
9.0	4589	6562	10184	12852	15493	22776	39448	57119
9.5	4820	6893	10697	13499	16274	23924	41436	59997
10.0	5052	7224	11211	14147	17055	25072	43424	62876
10.5	5283	7554	11724	14795	17836	26220	45412	65755
11.0	5514	7885	12237	15443	18617	27368	47400	68633
11.5	5746	8216	12750	16090	19398	28515	49388	71512
12.0	5977	8546	13264	16738	20179	29663	51376	74391
12.5	6208	8877	13777	17386	20959	30811	53364	77270
13.0	6439	9208	14290	18033	21740	31959	55352	80148
13.5	6671	9539	14803	18681	22521	33107	57341	83027
14.0	6902	9869	15317	19329	23302	34255	59329	85906
14.5	7133	10200	15830	19976	24083	35403	61317	88784
15.0	7365	10531	16343	20624	24864	36551	63305	91663
15.5	7596	10862	16856	21272	25644	37699	65293	94542
16.0	7827	11192	17370	21920	26425	38846	67281	97420
17.2	8382	11986	18601	23474	28299	41601	72052	104329

NOTE

1. No code stamp or “NB” on nameplate below 1.1 barg set.

Capacities for model 6252

NON-CODE AND ASME SECTION I STEAM (lb/hr), STEAM COEFFICIENT = 0.878

			Orifice,	are	in²
Set pressure	J	K	L	M	N	P	Q	R
(psig)	(1.414)	(2.022)	(3.138)	(3.960)	(4.774)	(7.018)	(12.155)	(17.600)
15	2027	2898	4498	5676	6843	10059	17423	25227
20	2346	3355	5207	6571	7922	11646	20171	29207
25	2666	3813	5917	7467	9002	13233	22919	33186
30	2986	4270	6626	8362	10081	14819	25667	37165
35	3306	4727	7336	9257	11160	16406	28415	41144
40	3625	5184	8045	10153	12240	17993	31163	45123
45	3945	5641	8755	11048	13319	19579	33911	49102
50	4265	6098	9464	11943	14398	21166	36659	53081
55	4584	6555	10174	12839	15478	22753	39407	57060
60	4904	7013	10883	13734	16557	24339	42155	61039
65	5224	7470	11592	14629	17636	25926	44903	65018
70	5550	7936	12316	15542	18737	27544	47706	69077
75	5879	8407	13047	16465	19849	29179	50537	73176
80	6208	8878	13778	17387	20961	30813	53367	77274
90	6867	9819	15239	19231	23184	34082	59028	85471
100	7525	10761	16701	21075	25407	37350	64689	93668
110	8184	11703	18162	22920	27631	40619	70350	101865
120	8842	12645	19624	24764	29854	43887	76011	110062
130	9501	13586	21085	26608	32078	47156	81672	118259
140	10160	14528	22546	28453	34301	50424	87333	126456
150	10818	15470	24008	30297	36525	53693	92994	134653
160	11477	16411	25469	32141	38748	56961	98655	142850
170	12135	17353	26931	33985	40971	60230	104316	151046
180	12794	18295	28392	35830	43195	63498	109977	159243
190	13452	19237	29854	37674	45418	66767	115638	167440
200	14111	20178	31315	39518	47642	70035	121300	175637
210	14769	21120	32777	41363	49865	73304	126961	183834
220	15428	22062	34238	43207	52088	76572	132622	192031
230	16087	23003	35700	45051	54312	79841	138283	200228
240	16745	23945	37161	46896	56535	83109	143944	208425
250	17404	24887	38623	48740	58759	86378	149605	216622

NOTE

1. No code stamp or “NB” on nameplate below 15 psig set.

Capacities for model 6252 – metric units

NON-CODE AND ASME SECTION I STEAM (kg/h), STEAM COEFFICIENT = 0.878

			Orifice,	area	cm²
Set pressure	J	K	L	M	N	P	Q	R
(barg)	(9.123)	(13.045)	(20.245)	(25.548)	(30.800)	(45.277)	(78.419)	(113.548)
1.0	904	1293	2007	2533	3054	4489	7775	11257
1.5	1115	1594	2474	3122	3763	5532	9582	13874
2.0	1325	1895	2940	3711	4473	6576	11389	16491
2.5	1535	2195	3407	4299	5183	7619	13197	19108
3.0	1745	2496	3874	4888	5893	8663	15004	21725
3.5	1956	2797	4340	5477	6603	9706	16811	24342
4.0	2166	3097	4807	6066	7313	10750	18619	26959
4.5	2376	3398	5273	6655	8023	11794	20426	29576
5.0	2592	3706	5751	7258	8750	12863	22278	32257
5.5	2808	4016	6232	7864	9481	13937	24139	34953
6.0	3025	4325	6712	8471	10212	15012	26001	37648
6.5	3241	4635	7193	9077	10943	16087	27862	40344
7.0	3458	4945	7674	9684	11674	17162	29724	43039
7.5	3674	5254	8154	10290	12406	18237	31586	45735
8.0	3891	5564	8635	10897	13137	19312	33447	48430
8.5	4107	5874	9115	11503	13868	20386	35309	51126
9.0	4324	6183	9596	12110	14599	21461	37170	53821
9.5	4541	6493	10077	12716	15330	22536	39032	56517
10.0	4757	6803	10557	13323	16061	23611	40893	59212
10.5	4974	7112	11038	13929	16792	24686	42755	61908
11.0	5190	7422	11518	14536	17524	25761	44617	64603
11.5	5407	7732	11999	15142	18255	26835	46478	67299
12.0	5623	8041	12480	15749	18986	27910	48340	69994
12.5	5840	8351	12960	16355	19717	28985	50201	72690
13.0	6057	8661	13441	16962	20448	30060	52063	75385
13.5	6273	8970	13921	17568	21179	31135	53925	78081
14.0	6490	9280	14402	18175	21911	32210	55786	80776
14.5	6706	9590	14883	18781	22642	33284	57648	83472
15.0	6923	9899	15363	19388	23373	34359	59509	86167
15.5	7139	10209	15844	19994	24104	35434	61371	88863
16.0	7356	10519	16324	20601	24835	36509	63233	91558
16.5	7572	10828	16805	21207	25566	37584	65094	94254
17.0	7789	11138	17286	21814	26298	38659	66956	96949
17.2	7876	11262	17478	22056	26590	39089	67700	98028

		Orifice,	area	in²	(cm²)
Set pressure	J	K	L	M	N	P
psig	1.414	2.022	3.138	3.960	4.774	7.018
(barg)	(9.123)	(13.045)	(20.245)	(25.548)	(30.800)	(45.277)
15	2217	3171	4921	6210	7486	11005
(1.0)	(1004)	(1436)	(2229)	(2813)	(3391)	(4985)

SELECTION GUIDE

Example:	6252	F	L	K	01	-	A	S	0020
Model 6252 6254
Connection type A FNPT x FNPT F 250# flange x FNPT K 250# flange x 125# flange
Orifice J N K P L Q M R
Inlet size G 1½” (38.1) H 2” (50.8) J 2½” (63.5) K 3” (76.2) M 4” (101.6) P 6” (152.4)
Variation (01 to 99) 01 Plain lever 02 Plain lever with gag
Design revision Indicates non-interchangeable revision Dash (-) if original design
Valve service A Steam ASME section I (model 6252 only) G Steam ASME section IV model 6254 only (model 6254 only - 15 psig/1.0 barg) K Air ASME Section VIII (model 6252 only) L Steam ASME section VIII (model 6252 only) N Non-code air/gas P Non-code steam
Spring material S Steel (plated)
Set pressure Model 6252 10 psig [0.34 barg] (0010) to 250 psig [17.2 barg] (0250) Model 6254 15 psig [1.0 barg] (0015)