Air eliminator and strainer

Overview

The LPG-X type Air eliminator and strainer, as auxiliary equipment for flow metering, is mainly used to filter the particulate impurities contained in the measured liquid, and can separate and exclude gases from it. In most cases, the measured liquid will contain various impurities and gases to varying degrees. These impurities and gases entering the flow meter will affect the metering accuracy of it. Therefore, in flow metering systems, especially high-precision flow metering systems, degassing filters are indispensable auxiliary equipment.

Structure

The Air eliminator and strainer is composed of several main parts, such as the housing, degassing valve, and filter screen. The housing should withstand the working pressure of the measured liquid and form a space that meets the requirements for filtration and degassing. The degassing valve controls the switch of the main and auxiliary valves through the upward, as well as downward movement of the floating ball to achieve the purpose of exhaust.

Working Principle of Air eliminator and strainer

When the liquid enters the degassing filter, it first impacts the baffle plate to disperse the liquid flow. The liquid and gas rises along the baffle plate to the top of the housing, forming a gas phase space. With the continuous expansion of the gas phase space, the liquid interface continues to decline, and the floating ball drops under the effect of its own weight, driving the valve stem to move, so that the auxiliary valve opens first to exhaust some gas. If the gas volume is greater than the gas discharged by the auxiliary valve, the floating ball will continue to drop, driving the valve stem to open the main valve and expel a large amount of gas. At this point, the liquid gas interface gradually rises. First, close the auxiliary valve, and the floating ball gradually rises to close the main valve. This repeatedly achieves the purpose of exhaust. The liquid separated by liquid and gas enters the filter screen, and the filtered liquid enters the flow meter.

Material Combination of the air eliminator and strainer

The degassing filter adopts a combination form of filter and degassing valve. The selection of filters depends on the pressure, and cast steel filters or cast iron filters can be selected. Welding filters can also be used according to user needs.

Technical performance

Nominal diameter mm	Mesh number	Nominal pressure MPa	Medium temperature ℃	Medium density kg/m3	Medium viscosity mPa.s	Pressure loss MPa
40	60	1.0 1.6 2.5	-20～120	≥0.80×103	2～500	≤0.07
50	60
80	40
100	40
150	40
200	40
250	20
300	20
350	20
400	20
450	10
500	10
550	10

Note: Special mesh number can be determined according to user needs.

Model Selection

Mark	Code	Description
Product Code	LPG-X	LPG-X Type Degassing Filter
Material	B C E	Stainless steel 304 Stainless steel 316 Cast steel
Diameter	40~400mm	Size from 40mm to 400mm
Pressure rating	1 2 3	1.0Mpa 1.6Mpa 2.5Mpa

Installation Requirements

a. .Installation dimensions

Material	Nominal diameter	Connection length L	Installation height A	Total height H	D		D1	n-φ
					Pressure	GB/T9112-2010
Welding	50	300	155	700	1.6	φ165	φ125	4-φ18
					2.5	φ165	φ125	4-φ18
	80	400	250	860	1.6	φ200	φ160	8-φ18
					2.5	φ200	φ160	8-φ18
	100	500	280	970	1.6	φ220	φ180	8-φ18
					2.5	φ235	φ190	8-φ23
	150	600	335	1150	1.6	φ285	φ240	8-φ22
					2.5	φ300	φ250	8-φ26
	200	786	395	1750	1.6	φ340	φ295	12-φ23
					2.5	φ360	φ310	12-φ26
	250	950	650	2000	1.6	φ405	φ355	12-φ26
					2.5	φ425	φ370	12-φ30
	300	950	700	2100	1.6	φ460	φ410	12-φ26
					2.5	φ485	φ430	16-φ30
	350	1200	750	2250	1.6	φ520	φ470	16-φ26
					2.5	φ555	φ490	16-φ34
	400	1200	750	2360	1.6	φ580	φ525	16-φ30
					2.5	φ620	φ550	16-φ34

Note: The import and export flange standards can also be manufactured according to relevant standards according to user needs

b. Installation requirements

• 1. The connection method between the degassing filter and the pipeline is flange connection.
• 2. The degassing filter should be installed in a place with minimal vibration, both indoor and outdoor.
• 3. The installation height of the degassing filter should not be lower than the one of the flow meter.
• 4. To facilitate maintenance and cleaning without affecting production, a bypass pipeline should be installed for the continuously running system.
• 5. The pipeline should be flushed clean before installation. Especially for newly laid pipelines, there may be scaly impurities or welding slag.
• 6. The flow direction of the liquid in the pipeline must be consistent with the direction indicated by the arrow on the degassing filter.
• 7. To prevent air pollution and accidents caused by the gas discharged from the degassing valve, a hose should be installed at the outlet of the exhaust valve to connect to the air collector.
• 8. To fully utilize the exhaust function of the degassing filter and ensure sufficient residence time of the medium in the chamber of the degassing filter, the distance between the pump on the pipeline and the degassing filter should not be too close, and should not be less than 20D.
• 9. To extend the service life of the degassing filter, the float valve can be removed for cleaning and refueling when cleaning the filter screen.

Operation Guide

• 1. Before liquid infusion, please check whether the installation of the degassing filter meets the requirements of the manual.
• 2. The flow rate and nominal pressure of the liquid should comply with the regulations on the nameplate.
• 3. Before starting the newly laid pipeline, the bypass valve should be opened. First, flush out the impurities in the pipeline.
• 4. Start-up steps:
• ⑴Open the bypass valve to allow the liquid to flow normally through the bypass pipeline,
• ⑵Close the shut-off valve of the degassing filer,
• ⑶Slowly open the upstream valve of the pipeline to allow the liquid with the degassing filter and flow meter,
• ⑷Slowly open the downstream valve of the pipeline. Gradually open the shut-off valve on the degassing filter, then observe whether the flow meter is operating normally,
• ⑸Close the bypass valve and adjust the flow rate with the downstream valve until the flow meter operates normally.
• ⑹For continuously running pipelines, the operating method of stopping operation is opposite to the sequence of opening.
• 5 When the pressure loss on both sides of the degassing filter is greater than 0.07MPa during operation, the filter screen must be cleaned in a timely manner.
• 6. To extend the service life of the degassing filter, the float valve can be removed for cleaning and adding lubricating oil when cleaning the filter screen.