LG throttling gear is a primary device in a differential pressure flow measurement system, which consists of a throttle, a pressure-receiving device and a straight pipe section. Throttling device is divided into standard throttling device and non-standard throttling device, the one is coincident with IS05167 and GB/T2624 standard is the standard throttling device, the others are non-standard throttling deivce.
When the pipe filled fluid flows through the throttling device in the pipe, according to the law of conservation of energy and the equation of flow continuity, the stream will form a local contraction at the throttle, thereby increasing the flow rate, static pressure reduction, static pressure difference ΔP(or named differential pressure) before and after the throttle. The greater the flow rate of the fluid, the greater the differential pressure generated before and after the throttle, and the amount of fluid flow is measured by measuring the differential pressure before and after the throttle.
Standard throttling devices should normally be used whenever possible, and non-standard throttling devices can be used only when the fluid Reynolds number is small or contains impurities.
Technical Parameters
Nominal diameter:DN15~1200(More than 1200 negotiated orders)
Nominal pressure:≤42MPa
Inaccuracy:±0.5%~±1.5%
Installation method:Flange connection, Welded connection(or customized)
Pressure method: Corner connection pressure (ring chamber or separate drilling), Flange pressure, Span pressure or else
Straight pipe: Upstream5~10D,downstream2~5D
Throttling device classification
| classification | Pressure method | Reference model | Nominal diameter(mm) | Nominal pressure(MPa) | Diameter ratio |
| Orifice plate | Small orifice plate | Corner connection pressure | LG-XH-40/25 | 15~40 | 1.0~42 | 0.1~0.7 |
| Flange pressure | LG-XF-40/25 | 25~40 | 1.0~42 | 0.15~0.7 |
| Standard orifice | Corner connection pressure | LG-BH-320/100 | 50~400 | 1.0~42 | 0.23~0.8 |
| LG-BH-100/65 | 50~250 | 1.0~42 |
| LG-BH-63/50 | 15~150 | 1.0~42 |
| LG-BZ-16/600 | 450~1600 | 0.6~2.5 |
| LG-BZ-10/50 | 450~1000 | 0.6~1.6 |
| Flange pressure | LG-BF-25/300 | 50~750 | 1.0~20 | 0.25~0.75 |
| LG-BZ-40/150 | 50~400 | 1.0~20 |
| Span pressure | LG-BJ-63/150 | 50~400 | 1.0~63 |
| Built-in orifice | LG-BFC-260/80 | 50~400 | 1.0~42 |
| Double orifice | LG-SH-16/100 | 25~400 | 1.0~10 | 0.19~0.82 |
| 1/4 round orifice | LG-HH-160/100 | 25~400 | 1.0~26 | 0.32~0.71 |
| Conical inlet orifice plate | LG-VH-16/100 | 25~200 | 1.0~4.0 | 0.12~0.32 |
| Round hole plate | LG-QH-6/1000 | 50~1600 | 0.25~2.5 | 0.32~0.71 |
| LG-QH-25/600 | 50~1400 | 0.25~2.5 |
| Nozzle | Small nozzle | LG-MH-40/32 | 25~40 | 1.0~26 | 0.3~0.71 |
| Standard nozzle | LG-PH-40/150 | 50~600 | 1.0~32 | 0.30~0.8 |
| LG-PH-63/200 | 50~600 | 1.0~32 |
| Long neck nozzle | LG-CJ-260/80 | 50~400 | 1.0~32 | 0.22~0.8 |
| Venturi tube | Venturi nozzle | LG-LT-16/150 | 65~400 | 0.6~2.5 | 0.32~0.78 |
| Classical venturi | Machining | LG-WT-6/200 | 50~600 | 0.6~40 | 0.38~0.75 |
| Rough welding | LG-WT-6/1200 | 200~2000 | 0.6~2.5 | 0.38~0.73 |
Small orifice plate, Small nozzle Reference size table
| Pressure Level | Size | DN15 | DN25 | DN32 | DN40 |
| PN25 | D | 95 | 115 | 135 | 145 |
| L | 126 | 128 | 143 | 149 |
| PN40 | D | 95 | 115 | 135 | 148 |
| L | 126 | 147 | 148 | 148 |
| PN63 | D | 105 | 135 | 150 | 165 |
| L | 126 | 152 | 159 | 177 |
| PN100 | D | 95 | 135 | 150 | 165 |
| L | 126 | 155 | 162 | 178 |
Note: The length L is based on the actual size, and the dimensions in the table are for reference only.
Company Profile and Certificate
