原装进口VIVOIL X1U3152DBBA 齿轮泵快速清关
R越大，调节流量的范围越宽,性能指标就越好.通常阀的R＝3,好的阀,如V型球阀、全功能阀,R可达1～2。小开度工作性能有些阀受到结构的限制,小开度工作性能差,产生启跳、振荡,R变得很小(即Qmin很大)，如双座阀、衬胶蝶阀。好的阀小开度应有微调功能，即可满足很小流量的调节，且工作又要求十分平衡，这类阀如V型球阀、偏心旋转阀、全功能超轻型调节阀。流量系数Kv流量系数表示通过流量的能力,同口径Kv值越大越好，尤其是球阀、蝶阀、全功能阀,它们的Kv值是单座阀、双座阀、套筒阀的2～3倍。调节速度满足系统对阀动作的速度要求。2切断功能切断由阀的泄漏量指标来表示,切断通常指泄漏量小于.1％,它反映阀的内在的质量.在阀的使用中,对国产阀泄漏量大的呼声反映很大。3克服压差功能它通常用阀关闭时的允许压差来表示，允许压差越大，此功能也就越好。如果考虑不周到，阀芯就会被压差顶开，造成阀关不到位，泄漏量超标。保证阀切断就必须克服阀关闭时的工作压差。通常单密封阀的允许压差小，如单座阀、角形阀、隔膜阀、三通阀；双密封的阀和转动类的阀的允许压差大，如双座阀、套筒阀、球阀、全功能超轻型阀。
KOBOLD DW-N-AU-FL Nr.:560762
FINDER继电器403190120303
SGL(KCH) Elbow 90 PP/FRP DN200 PN10,laminate ends 管接头
RIEGLER 15.DMA.50150
ILME ILMMAO 16 X32
SCHNEIDER XY2CEDA196H7
eckerle EVL 12 3603 L7 W 110 电子镇流器
英国ONDRIVES变速箱和减速器E40-X
OMRON F39-JGR3K-RE
Gefran-2019 F038607 GFW-3PH-100-600-0-0-2-0-1-1-0
小强工控 CARLO GAVAZZI EM21072DAV53XOSX
Turck WAK3-5/P00,NO:8007036 电缆
Eaton Moeller 259137 NZML3-VE250
Gefran-2019 F304384 850V-R-RRR-0-1-02-3-00-00-0-00
SCHNEIDER 9001SKP38LRR31
Eaton Moeller 132854
FINDER继电器850400120000
Emiltrafo 408
EA ZA310064-NE052100
MD MICRODETECTORS MDI38F 1975
UNIVER PSR622
Gefran-2019 F050242 TC1-A-1-K-5-A-H 040X000G00210XA
RIEGLER TFT 130-10
OMRON ZX2-LD50V 0.5M
英国ONDRIVES变速箱和减速器E50-4A-LH
Eaton Moeller 6D16 SICHERUNG-D1 6A T GL/GG 500VAC E16
TWK编码器CRF58-4096G4096E01
Eaton Moeller FNM-1-1-4
Eaton Moeller 254970 NWS-BDA/8800
UNIVER RP2100320200
UNIVER RT1300401200M
RIEGLER 168.012-8
JAQUET DUalTach T501 30000RPM 1000HZ
DG2D3125020/BR FG1323 MEMG2S346282015/AX
DOLD安全继电器62423 GI9014 3AC200-440V UH DC24V 22KW
STEMMER FP-EX2 / C80001
BECKHOFF ES3054
Eaton Moeller 3-6WFDH6160
LIKA编码器IT65-Y-5000BND2CR 5000PPR-RAD
MD MICRODETECTORS MDI38F 942
Eaton Moeller 197811 E57P-30UNC15-C2
SELET传感器K01G30PSC
Gefran-2019 F044143 TC1M-B-1-J-2-C-I-D-2 100X000X00100XX
OMRON A22NW-2RM-TWA-G102-YE
LEUZE 68001422 MLC510R40-2250
RIEGLER 650 F/M
小强工控 CARLO GAVAZZI PS42L-PO11LN-M00
SCHNEIDER MTN5250-6034
UNIVER J12A660350A
OMRON TL-W5E2
ILME ILPEW 32104 PQ
RIEGLER 11081 E-ES
SCHNEIDER MGU3.037.18P
OMRON E2E-X6MD18-M1TGJ-T 0.3M
MD MICRODETECTORS MDI63A 2027
UNIVER阀门PSK200290进口阀门
AD311025 DL2D3118040/FL-TA FG614023
UNIVER BDF-4100
mecatrb 7513231 ELS460 压接钳
AECO SIP000024 SIPA8-C2 NPN NC H1
RIEGLER 637.201
小强工控 CARLO GAVAZZI CM30D1A
DOLD安全继电器53141 BA9053/010 AC1-10A AC400V 0-20S
Gefran-2019 F053672 TK-C-1-V-B02C-M-V 2130X000X00
小强工控 CARLO GAVAZZI PD30ETT15NAM5SA
Eaton Moeller 121471 M22-PVS60P-MS*
schunk 0309185 1416 307752
Electronicon E63.G85-104G10
BONFIGLIOLI BNIOOLA4
ZILLER 6220 JV (NUP 2220 JV) 密封件
MD MICRODETECTORS MDI58F 2653
SCHNEIDER MTN507244
MD MICRODETECTORS MDI58G 969
Gefran-2019 F020695 TR6-D-2-B-C-C-J-D-2 000X000X00200XA
OMRON E39-R52
MD MICRODETECTORS MDI63G 696
OMRON A22NN-BPA-UAA-G101-NN
SCHNEIDER ZBY0123
LEUZE 50025609 PRK 95/44 L.4
SCHMERSAL 103006656 PS116-Z11-ST-K210
STRACK 446X546-F1-56-1730 178389
小强工控 CARLO GAVAZZI RGS1A60D92MKEHT
SCHNEIDER XCKJ567433287
UNIVER KL2001000025M
OMRON E2V-X15B1 2M
SCHNEIDER MTN584043
SCHNEIDER ZB5FH43C1
小强工控 CARLO GAVAZZI RA4025H10NCS
SELET传感器B02E124PCC5
Electronicon 3207332b40
RIEGLER MSN290MS38
Gefran-2019 F059572 2500-0-1-0-0-2-1
STAHL 9001/01-252-060-141
SCHNEIDER H367AWKVW
美国hastings通用操作杆TIE STICKS 4684-6
OMRON FJ-SCG
UNIVER K2000320095
KARL KLEIN 51331-1.030
Gefran-2019 F041422 MK4-C-B-0500-A-4 00002X10000X0XX
STAHL 130819 8040/1180X-10L07BA08 Befehls-/Meldeger?t 自动控制器
Ashcroft 100=T5500=S=D=04=L=0/6000=KPA=YW=AJ 压力表
SCHMERSAL AZM 415-22XPK14H-9725 24VAC/DC Art.-Nr. 101136087 感应传感器
SCHNEIDER XALK188H26
SCHNEIDER BCH2MM0520CF6C
hastings 01-061
SCHNEIDER RE22R1MKMR
SCHNEIDER MGU3.201.30N
Gefran-2019 F056677 GQ-15-24-D-0-4 (230V/15A)
MD MICRODETECTORS MDI38F 524
MD MICRODETECTORS MDI40A 652
Rechner EGI-130 115/230 VAC 感应传感器
OMRON JZSP-CVP27-03-E-G5
keystone 014150222WMDB00 蝶阀
KUHNKE 65.111 NW1 0(24VDC 4.5W) 油压传动阀
小强工控 CARLO GAVAZZI PS31L-MT12R2-M00
OMRON R88M-1M1K520H-BS2
MD MICRODETECTORS MDI63D 1771
OMRON E3RB-RP21-E013
FINDER继电器486181100060SPA
RIEGLER 11.518-8
SCHNEIDER ZCMD21L2
RIEGLER 258.04/1
MD MICRODETECTORS MDI58G 973
原装进口VIVOIL X1U3152DBBA 齿轮泵快速清关
三防针刺毡除尘布袋的三防即为防水、防油、防静电，即在防静电针刺毡的基础上增加拨水、拨油功能，适用于含湿量较大的场合，如钢铁厂高炉喷煤粉、水泥厂、电厂输煤系统等。高强低伸工业丝作基布，使强度大幅提高。选用细旦纤维，孔径缩小，孔隙率高，过滤精度高。选用优等聚酯纤维，耐酸碱耐水解性均得到增强。表面处理更光滑，具有覆膜滤料的表面过滤效果。运行阻力小，节省能源。除尘布袋随着粉尘在滤料表面的积聚，除尘器的效率和阻力都相应的增加，当滤料两侧的压力差很大时，除尘布袋器会把有些已附着在滤料上的细小尘粒挤压过去，使除尘器效率下降。
ASM GmbH WS10 1250 10 PP530 位移传感器
英国ONDRIVES变速箱和减速器UPHG1.0-67RPH-K
OMRON H7GP-T
EA ZA310026/HT-ED630632
Gefran-2019 F074119 KE1-6-M-B35U-1-4-D-I-E 2130X000X00
SCHNEIDER EVB1A22P2KI
FHF 22421205
MD MICRODETECTORS MDI63G 2252
Gefran-2019 F072318 1850V-R-RRR-0-2-03-5-M0-00-1-FB
SCHNEIDER ZB6CGJ
hastings 7714 GROUND/JUMPER TESTER COMPLETE WITH STANDARD ELECTRODE
BECKHOFF CP7221-0000-0050
Gefran-2019 F304407 850-D-RR0-0-0-03-3-00-00-1-00
Eaton Moeller 91885 T5B-5-8345/EA/SVB
Gefran-2019 F023975 TR1M-B-2-B-1-C-E-A-2 040X000X00050XX
OMRON MMF-06D24DM-AC5
RIEGLER 220.038-12
小强工控 CARLO GAVAZZI CTD8S12505AXXX
SCHNEIDER ABE7CPA412
RELECO C7-A20X/DC48V R .
RIEGLER 855.012-16 ES
OMRON A22NL-BMM-TAA-G002-AE
MD MICRODETECTORS MDI63D 2643
SCHNEIDER LC1D096FLS207
Gefran-2019 F019859 TR6-B-2-A-C-C-J-D-2 000X000X00600XA
OMRON 97-000012-02
OMRON H3RN-2 24VAC
SCHMERSAL 101206707 SLC 420-E/R0970-30-RFBM
Eaton Moeller 174197 IKA-1/12-ST
SCHNEIDER BSH1001T22F1A
MAXON电机352990
AECO SEH000050 SHC/P-12L PNP NO
BECKHOFF ZS1052-0630
Eaton Moeller 184667 XSMRDB06
MD MICRODETECTORS MDI38G 443
IPF AM000032
ACAM PT2G-SM5.5
MD MICRODETECTORS MDI63D 441
OMRON CPM2C-10CDR-D
EUCHNER CES-A-BBN-C04-115271
BURKERT 电磁阀240932
SCHNEIDER MTN471425
BECKHOFF C9900-H566
UNIVER K2000630220GM
Eaton Moeller 13523 T0-4-11/EZ
SCHNEIDER MVS32N3NW5L
MD MICRODETECTORS MDI58F 871
MAXON控制器586137
BURKERT 电磁阀141534
UNIVER G-6255
SCHNEIDER XX7F1A2NAL01M12
SCHNEIDER ZB6CA4N
SCHNEIDER VW3AE0807
SCHNEIDER SSP1A125BDT
SCHNEIDER VLVAW0N03504AK
SCHNEIDER NSYPLAZ573G
英国ONDRIVES变速箱和减速器BLHI30-1
SCHNEIDER LC1D098R7
ILME ILZQE 322
RIEGLER SRV1025MS33CH
Eaton Moeller 177880
SCHNEIDER ZCD31
RIEGLER 351.510-2
SCHNEIDER VLVAF2P03508AG
SCHNEIDER CA2SK11P7
UNIVER R12063040M
SCHMERSAL 1175347 感应传感器
BURKERT 2835 A 4.0 FKM MS G1/2 8bar 24VDC 16W 10005056 (MB-271)
SCHNEIDER ZA2BG5
STRACK 446X446-F1-76-2311 178225
MD MICRODETECTORS MDI63F 1860
UNIVER RS1000500400
SCHNEIDER MTN4030-6551
OMRON A22NS-3RL-NYA-G120-NN
SCHNEIDER ZB5AG0K
BURKERT 电磁阀144800
SCHMALZ VS-V-EM-M8-4 10.06.02.00456/2
Eaton Moeller 125772 SVX150A1-5A4N1
hydac N15DM002;1251590 滤芯
UNIVER AG-3004
DOLD安全继电器1910 AI 953N.0082 AC50/60HZ 42V 0,05-1S
GEORGII KOBOLD IEC38 KOD346-A IMB3
LEUZE 50119971 CML720i-R20-2070.R/CN-M12
SCHNEIDER XS1N12PA349D
SCHNEIDER BSH1402T32A2A
OMRON NP025S-MF1-7-1E1/R88M-K75030H
OMRON E4C-DS80L
UNIVER K1000400025M
Eaton Moeller 177837
Eaton Moeller 178069 XTPFCUV1-H350MW600
LEUZE 63000204 S200-P5C1-M20
OMRON A22NZ-3BM-NRA
Eaton Moeller 114812 BPZ-MPL300-425
FEAS Netzteil SNT1415
UNIVER S1011255600
UNIVER W1000630110
RELECO MRI32R/UC110-240V
SCHNEIDER LUCD05ES
Eaton Moeller 226547 ZSD-H/P/SI/KLP
OMRON E5AC-QQ4A5M-011
BECKHOFF KL2634
小强工控 CARLO GAVAZZI PS42L-AT02BR-H00
VIVOIL齿轮泵X1I2573SIID
供应原装进口意大利VIVOIL齿轮泵X2P4501EOOA
BECKHOFF CP7232-0001-0060
TECNA 9403G
MD MICRODETECTORS MDI38G 1847
Eaton Moeller 166832 E59-A12A104C02-CV
Eaton Moeller 100513 NZM3-4-XKP
UNIVER KD1000630450M
英国ONDRIVES变速箱和减速器OFG40-12A
SCHNEIDER A9N19643
SCHNEIDER MTN2510-0460
FINDER继电器601380245054
BECKHOFF ZK1090-6191-0025
Eaton Moeller LPJ-125SP LOW PEAK CLASS J T/D LPJ-125SP
EA ZP311009
Gutekunst + Co.KG D-257C 弹簧
SCHNEIDER LC2D12FE7
RIEGLER 580FRC1-14-4
SCHNEIDER LXU5.461.18PPZ
SCHNEIDER ZB4FK1313
CEAG13362632/25 DM3301721-01/07-G IW111624
MD MICRODETECTORS MDI63D 628
MD MICRODETECTORS MDI38G 2042
Schlick 930/7-1-S45 D 4.1065/5 喷嘴
RIEGLER 226.02-21,0
MD MICRODETECTORS MDI63G 412
FINDER继电器405290062300PAC
Eaton Moeller 266217 NZM4-XUHIV24AC
EA ZK311003-NE052100
MD MICRODETECTORS MDI63F 2869
MD MICRODETECTORS MDI58G 1501
SCHNEIDER BCH1801N02F1C
KOBOLD PDD-553R4B085
MD MICRODETECTORS MDI58C 2940
UNIVER KD1000320040M
Gefran-2019 F018149 TR1-B-1-B-5-A-I-A-1 010X000X00050XX
RIEGLER 252.23
Eaton Moeller 229991 DILM95-XSP(208V60HZ)
LEUZE 549855 UDC-900-S2
DUNKERMOTOREN DR62.0×80-4 SNR88183 05170
小强工控 CARLO GAVAZZI CTD8S10005AXXX
Gefran-2019 F068781 GSFSMR1800LA0 0000X00
FINDER继电器405190122001PAC
VIVOIL齿轮泵X2M4119CRRE
OMRON V400-W24 5M
Eaton Moeller 266664 NZM2-XSM-L
SCHNEIDER BRS368WS0610
SCHNEIDER A9N18369
VIVOIL齿轮泵X2R4331IRRE
原装进口VIVOIL X1U3152DBBA 齿轮泵快速清关
为此，人们开始探索现场搪瓷设备修补的方法。研究开发修补材料来满足修补的需要。国外产品有索泰，福世蓝，贝尔佐纳等，国内产品有德邦，天山，犟力，ZH等，但这些修补剂修复的局限性很大，耐腐蚀性差，不能适应搪瓷设备冷热剧变下的修复效果，使用寿命短。工程师经过十几年的研究和实践，研究出里mty系列新材料修补剂和修补新工艺。在短时间内经济可靠地修补搪玻璃设备，成功地解决了搪瓷设备现场修复的技术难题。修补剂的创新为修补剂不可比拟的。
UNIVER K2000500105M
SCHNEIDER XCMN1435806
LEUZE 50134370 PRK15.D/4X-M12
R.STAHL 8510/141-05-335-070
小强工控 CARLO GAVAZZI PS42L-BS11RT-H00
供应进口法国HPI齿轮泵P1AAK2018HA2006HL30A...
BECKHOFF EL6740-0010
BURKERT 电磁阀41163
MD MICRODETECTORS MDI63D 2395
OMRON E5EC-QX4D5M-000
OMRON XW2Z-10MJ-G4
RIEGLER SP 10-1000KSD
HBM 1-U9B/100N
SCHNEIDER BSH0401P17F2A
SCHNEIDER XMLB300E2S12
SCHNEIDER KTC3200LP4C2
ILME ILCKSF 04
SCHNEIDER DF3FA04
Z-Laser Z5M18B-F-635-x60
SCHNEIDER LA2KT2U
ILME ILMFO 10.25
ZIMMER WER03LF09-B
Spraying HB1/4VV-8005 喷嘴
SCHNEIDER KBB40AF
Gefran-2019 F042038 TC1M-A-1-K-5-F-E 020X000X00050XA
Eaton Moeller 236010 PXL-B2,5/1
RIEGLER 259.5599
MD MICRODETECTORS MDI58F 971
Turck RUC30-M30-2AP8X-H1151,NR.1840020 接近开关
SCHNEIDER VDI4510
AG111023 DL2D3126020/FL-TA FS000610
DA2D3126040 DM3405061-03/16 KU300009
SCHNEIDER GV4LE07S6
OMRON MY4ZIN-D2 12VDC (S)
英国ONDRIVES变速箱和减速器UPHG1.0-51RH-K
SCHNEIDER SL40725
RIEGLER 518.120-18
EUCHNER MGB-H-AA1A1-R-100464
SCHNEIDER NSYDBN3025D
JUNG 1058108
RIEGLER SKR-3
MD MICRODETECTORS AES/AP-3A8F
Electronicon E62.K85-903D10
OMRON S8VS-06024
FINDER继电器223200241540
OMRON A22NN-RMM-NYA-G111-NN
ILME ILCHI 06 LC
Gefran-2019 F057720 MN1-6-M-B07C-1-3-D 2130X000X00
RELECO C18-A15PTL/AC115V
RIEGLER 567-6
Dopag C-400-25-91 减压阀
SCHNEIDER WDE000620
SCHNEIDER BMH1904P22F2A
OMRON FLV-BR38037W
DOLD安全继电器33357 EO7864.82 AC/DC24V+AC220-240V
Eaton Moeller 290173 LS-11/LS
UNIVER VL12211400400
SCHNEIDER XEDS2111
SCHNEIDER LC2DT326M7
MD MICRODETECTORS MDI58G 2756
ALRE FTRCUd-210.021#28
ILME ILAFP 29
UNIVER K2000630900
IPF VK001034
SCHNEIDER K1F013NL
BECKHOFF KS1498
OMRON XS3F-M422-410-A
MD MICRODETECTORS MDI63D 202
AECO C30000168 SC30SP-A20 TE10' NO/NC H
MD MICRODETECTORS MDI63A 2696
Electronicon 275.169-707700
Eaton Moeller 207075 T0-1-8200/I1-RT
SCHNEIDER ZB4BG4K3342E
Eaton Moeller 103097
OMRON A22NN-RMA-UAA-G202-NN
SCHNEIDER ISM10504P
RIEGLER 359.014-6
SCHNEIDER ISM20517
UNIVER KL2010800160M
ILME ILPEW 6365 SVX
小强工控 CARLO GAVAZZI G34960004700
SCHNEIDER TSXEFCF01
SCHNEIDER A9F05332
SCHNEIDER XUSL4E4BB091NM
VIVOIL齿轮泵X3P7831IEEA
UNIVER KE2000500450M
SCHNEIDER MTN508246
SCHNEIDER XVEL6B7
Gefran-2019 F002973 PVC 2X1 KX DIN 100M
MD墨迪 FAI6/BN-2A90° Energ. 400 mm NPN Q/QN plast. cable 2m axial
WALTHER 1-MD-006-2-WR013-21-1
TWK编码器SWF-5B-07 5米
OMRON E5EC-QR4A5M-010
SCHNEIDER BRS39AWS0709
UNIVER K2000321000M
R+W 618.6740.644
SCHMERSAL 101171125 AZM 161-B1S
SCHNEIDER V6
RELECO C10-A15X/DC24V R ..
SCHNEIDER 29349C
SCHNEIDER KTC3200ER31
SCHMERSAL 103016239 SLC240COM-ER-1290-14
SCHNEIDER XMLC500E2S11
OMRON MP-202-RG
ILME ILMAV 06 LG32
小强工控 CARLO GAVAZZI ICB30L50N22NOM1
英国ONDRIVES变速箱和减速器E40-20-12-LH
LEUZE 50123178 CML730i-R10-640.R/PB-M12
IIYAMA T1732MSC-B1X
DK340306374 FG4028 MGF5400050
SCHNEIDER LZ2H6X5FU
供应进口法国HPI齿轮泵P1AAK0075FL20B01N
Gefran-2019 F065573 RK-5-A-A-2000-E 0000X240X00X0XX
RIEGLER 855.018-6
FINDER继电器405270602001
ILME ILCAO 10 YX29
MD MICRODETECTORS MDI58B 2287
Gefran-2019 F053034 TC6-D-1-J-C-A-J-C-2 000X000X00150XX
RIEGLER 140.84-PP
Gefran-2019 F030117 TC1-B-2-J-5-A-H-B-1 020X000X00150XX
Eaton Moeller Jun-35
Eaton Moeller 217334 ZSD-BPKT/T/07
R+W BKM-400/35/40
SCHNEIDER DE9PM1202VR
SCHNEIDER TBUCLICTRS01SWK
SCHNEIDER TM251SPS06
OMRON H3YN-2-B DC125
RIEGLER 130.014-8
MD MICRODETECTORS MDI63G 1163
PILZ Nr:774310 自动控制器
OMRON A22NK-3BM-01GA-G221
MD MICRODETECTORS MDI58C 1959
MD MICRODETECTORS MDI63F 1971
RIEGLER TFT 130-11434
HARTING 09 99 000 0620 插头
SCHNEIDER NSYS3DBFL3417
hastings 05-977
hydac 0660 R 010 BN4HC 滤芯
EUCHNER 2019 sk euro545.58
Eaton Moeller PV-80A-01XL-15
Celsa 70054-1366 PQS96x24 0-20 Ma scale horizontal: 0-500kW
Rockwell Nr:440N-Z21SS2B
小强工控 CARLO GAVAZZI UA30CLD25PO
FLUCOM电磁阀MCD 28/2202
ILME ILCX 8 J6M
UNIVER K2000400100F
BERNSTEIN 611.6119.047
Gefran-2019 F026391 TC1M-A-3-K-5-F-E 030X000X00400XX
SIEBERT S302-F3/06/0R-101/0A-YR
SCHNEIDER BCH2LH2033CA6C
SELET传感器L70500-KPU
DI-SORIC LW20 DI-EL NPN
SCHNEIDER BSH1403P22A2A
JUMO 701150/8-01-0253-2001-25/005.058
ETDLAN1G-AD
AFAG CS8/30SD 50035820
SCHNEIDER NSYCEWX15K2P4
LEUZE 50135805 LCS-1M30T-N30NNO-K020T
UNIVER K2000400355
Gefran-2019 F043736 TK-E-3-P-B16U-H-V 2130X000X00
Eaton Moeller 100423 DILM150-XCT
STAHL 8581/11-406
SCHNEIDER G3HT15KHB2S
Eaton Moeller 107261 NZM2-XRAVR
OMRON E2A-S18LS08-M1-B3
RIEGLER MV 1216/0
RIEGLER 222.04-6,0
BURKERT 电磁阀146476
ACAM PTSM 5.6 Sensor
SCHNEIDER BSH0553T22F1AUNIVER RQ4000320420
BEI编码器GHU920-5000-002 SMW 089380 BURKERT 电磁阀184702 KOBOLD 41R57 250V 1.5A 100W
原装进口VIVOIL X1U3152DBBA 齿轮泵快速清关
为什么双座阀小开度工作时容易振荡？对单芯而言，当介质是流开型时，阀稳定性好；当介质是流闭型时，阀的稳定性差。双座阀有两个阀芯，下阀芯处于流闭，上阀芯处于流开，这样，在小开度工作时，流闭型的阀芯就容易引起阀的振动，这就是双座阀不能用于小开度工作的原因所在。为什么双密封阀不能当作切断阀使用？双座阀阀芯的优点是力平衡结构，允许压差大，而它突出的缺点是两个密封面不能同时良好接触，造成泄漏大。如果把它人为地、强制性地用于切断场合，显然效果不好，即便为它作了许多改进(如双密封套筒阀)，也是不可取的。
