Calculation Of minimum Inlet Pressure

If the pressure in pump is lower than the vapour pressure of medium, cavitation will occur, which will affect the performance of pump. To avoid the cavitation and ensure the pump inlet has a minimum pressure, maximum suction head should be calculated as following:

H = Pbx10.2-NPSH-Hf-hv-Hs

Pb: Atmosferik presyon, ba (Nan sistèm tiyo fèmen, li ka konsidere kòm presyon nan sistèm);
NPSH: Net positive suction head, m (Value at maximum flow of Q-NPSH curve);
Hf: Suction pipe line loss (Value at maximum flow of corresponding pipeline);
Hv: Medium vapour pressure, m (Medium vapour pressure at corresponding temperature, the default medium is water, as shown in figure4 on the right );
Hs: Sekirite Marge, m, valè jeneral se 0.5.
Calculation result: if H is positive, the pump is installed in suction way, otherwise, it is installed in downdraft way.

Remak: Li pa nesesè fè pi wo pase kalkil dapre kondisyon jeneral yo. Se sèlman lè nou itilize ponp nan sitiyasyon sa yo nou bezwen kalkile H la:
1. Medium temperature is high;
2.The vitès nan koule se pi gwo pase valè rated;
3.Saks tèt se gwo oswa inlet tiyo ki long;
4.System pressure is small;
5.Inlet condition is bad.

Selection Of Pumps

Seleksyon ponp yo ta dwe baze sou:
Devwa pwen nan ponp lan.
Done dimansyon tankou pèt presyon kòm aresult nan diferans wotè, pèt friksyon nan tiyo a,
Pump efficiency etc.
Materyèl ponp
Pump connections
Commonly used mechanical seal configuration tables

1. Devwa pwen nan ponp lan:

Soti nan yon pwen devwa li se posib yo chwazi yon ponp sou baz tablo yo koub yo montre nan "performancecurves / teknik & quot; done.

2. Dimensional data:

Lè gwosè yon ponp sa yo dwe pran nan kontablite: • Obligasyon koule ak presyon nan pwen trase la. "Pèt Pèt kòm yon rezilta nan diferans wotè." Pèt friksyon nan tiyo a (Hf) (Refere nan Fig.1) Li kapab. "Pi bon efikasite nan pwen devwa estime a." NPSH valè. "Pou kalkil valè NPSH a, gade tablo korespondan tablo.

3. Efikasite ponp:

Before determining the best efficiency point, the operation pattern of the pump needs to be identified. If the pump expected to operate as the same duty point, then select a BL pump which is operating at a duty point corresponding with the best efficiency of the pump.
Kòm se ponp lan ki menm gwosè ak baz la nan koule ki pi wo a posib, li enpòtan toujou gen pwen an devwa sou bò dwat la sou koub la efikasite (ak) nan lòd kenbe efikasite segondè lè koule a desann.

4. Pump material:

Seleksyon nan koneksyon ponp depann sou presyon rated ak tiyo travay. ponp lan ofri yon pakèt koneksyon fèkseptab tankou:

5. Souvan itilize mekanik tab konfigirasyon sele

Jaden aplikasyon

Shaft seal type

Materyèl sele aks

Nòmal

Special

1

2

3

4 5

Type key

Rotating part

Kòd

Estasyonè pati

Kòd

Elastomers

Kòd

Konpresyon prentan

Collor

Kòd

0℃ to +90℃ clean water

â-

Graphite

A

SiC

S

FPM

F

SUS304

C

ASFC

0℃ to +90℃ clean water

â-

twalet

W

Graphite

A

FPM

F

SUS304

C

WAFC

+ 90â "ƒ pou + 120â" ƒ rezistans korozyon

â-

SiC

S

SiC

S

EPDM

E

SUS304

C

SSEC

up to 0℃

â-

twalet

W

twalet

W

EPDM

E

SUS304

C

WWEC

Mechanical seal type	Modèl ponp	d1	d2	h
NJK	BL (T) 2/4	12	12	55
	BL (T) 8/12/16/20	16	16	57.5
	BL(T)32/45/60/90	22	22	72
NDA	BW (J) 2/4	12.7	16	32
	BW (J) 8/16	17.4	20	33.5