Hydraulic pump for testing

Abstract

A hydraulic test pump 1 with a container 2 for a test fluid, a connection device 10 for connection to an external piping system, a mechanical pressure gauge 4 hydraulically connected to the connection device 10, and a manually operated piston pump 13 hydraulically connectable to the connection device 10 for pumping a test fluid from the container 2 into an external piping system connected to the connection device 10, further comprises an electrical pressure sensor 18 in hydraulic connection to the mechanical pressure gauge 4.

Description

Technical field

[0001] The present disclosure relates to a hydraulic test pump and in particular a hydraulic test pump with a manually operated pressure generating device and an analog pressure indicator.

[0002] Hydraulic test pumps, or simply test pumps, are specific hydrostatic testing devices primarily used to check the leak tightness of heating, domestic hot water, or drinking water installations. Such testing may be necessary after new installations or repairs to prevent unwanted subsequent leaks and resulting water damage.

[0003] Typically, hydraulic test pumps with a manually operated or electrically driven pressure generating unit are used in such scenarios. Some of these are equipped with mechanical analog instruments for displaying the applied test pressure.

[0004] In this case, it is the user's responsibility to read the display after applying the test pressure and to determine an appropriate waiting period, after which, if the pressure reading remains unchanged, a tight installation can be assumed.

[0005] The appropriate waiting time may be stipulated by regulations and / or depend on the operating conditions and working methods. Accordingly, under certain circumstances, operator support may be necessary to ensure efficient adherence to the waiting time.

[0006] A hydraulic test pump according to the preamble of claim 1 is known from CN 202 203 067 U. concepts

[0007] The technical concept of claim 1 addresses this need in a fundamental way. Embodiments and alternatives are specified in the dependent claims. Brief description of the characters

[0008] Two exemplary embodiments of a drive unit using one or more of the concepts outlined above are explained in the following section with reference to the attached drawings. These show: Fig. 1 shows an exemplary hand-operated hydraulic test pump in a perspective view; Fig. 2 shows a schematic hydraulic and electrical circuit diagram for the hydraulic test pump according to Fig. 1 ; Fig. 3 a possible alternative to the section "X" in the hydraulic circuit diagram of the Fig. 2 Fig. 4 shows a schematic hydraulic circuit diagram of an external piping system with a leakage situation; Fig. 5 shows a schematic hydraulic circuit diagram of an external piping system with an internal equalization situation; and Fig. 6 shows a diagram for two simple mathematical models of the pressure-time dependence in the situations of Fig. 4 und 5 . Examples of implementation

[0009] According to the Fig. 1 An exemplary hydraulic test pump 1 comprises a cuboid basin 2 for receiving the test fluid. The reservoir 2 is partially covered at the top by a valve plate 3.

[0010] The instrument panel 3 includes a receptacle for a mechanical pressure gauge 4. In this exemplary embodiment, the mechanical pressure gauge 4 is an analog circular pointer instrument. In particular, the analog circular pointer instrument 4 can be equipped, in a manner known per se, with a trailing pointer for holding a maximum reading.

[0011] Furthermore, two rotary handles 5, 6 and a lever drive 7 are arranged on the control panel 3. Finally, the control panel 3 includes a hydraulic outlet 8 to which a flexible pressure hose 9 is connected.

[0012] The flexible pressure hose 9 has an end connection 10, which can be used to establish a tight connection with a compatible test port on an external piping system under test. In a simple case, the connection 9 can be a screw fitting with a flat gasket and a union nut. These details are not shown in the drawing.

[0013] Some functional units relevant to the overall function of the hydraulic test pump 1 are located below the valve plate 3 and are therefore in the Fig. 1 likewise not discernible. Since the overall function depends solely on the functional contributions of these functional units, their explanation here will be limited to those shown in the schematic hydraulic circuit diagrams of the Fig. 2 , 3 und 4 Recognizable relationships are limited. Suitable implementation options for these functional units are known from the relevant technical literature.

[0014] According to Fig. 2 The flexible pressure hose 9 is connected via the hydraulic outlet 8 and a subsequent pipeline 11 to the pressure gauge 4 and a first valve 12. In this exemplary embodiment, the first valve 12 is mechanically connected to the rotary handle 5 on the control panel 2. An operator can open the valve 12 using the first rotary handle 5, thereby establishing a connection between the pipeline 11 and a hand pump 13. The operator can close the valve 12 using the rotary handle 5 to interrupt the connection between the hand pump 13 and the pipeline 11.

[0015] Pipeline 11 also leads to a second valve 14, which is connected, for example, to the second rotary handle 6 on the valve plate 2. An operator can open valve 14 using the second rotary handle 6, thereby establishing a connection between pipeline 11 and a relief line 15. The operator can close valve 14 using the second rotary handle 6 to interrupt the connection between the relief line 15 and pipeline 11.

[0016] The hand pump 13 is connected to the lever drive 7. By actuating the lever drive 7, an operator can use the hand pump 13 to pump liquid from the reservoir 2 via the riser pipe 16 to the first valve 12. In the exemplary embodiment, a filter 17 is arranged in the riser pipe 16 to prevent any contamination of the hand pump 13 and the hydraulic functional units located downstream of it.

[0017] The hydraulic functional units described above enable manual pressure testing through the following exemplary operating sequence. First, an operator fills the reservoir 2 with a sufficient quantity of a suitable measuring fluid, e.g., water. Then, the operator opens the first valve 12 and the second valve 14.

[0018] The operator then holds the free end 10 of the pressure hose 9 over the reservoir with one hand and operates the hand pump 13 using the lever 7. This pumps the measuring fluid from the reservoir 2 through the first valve 12 into the pipeline 11. From there, part of the measuring fluid flows back into the reservoir 2 via the second valve 14 and the relief line 15. Another part of the measuring fluid flows back into the reservoir 2 through the pressure hose 9. These flows remove air bubbles from the hydraulic system.

[0019] As soon as the measuring fluid flows out of the pressure hose 9 without bubbles, the operator stops operating the hand pump 13. They close the second valve 14 and connect the free end of the pressure hose 9 to the terminal connection device 10 with the external piping system to be tested.

[0020] The operator then builds up pressure in the pipeline 11, the pressure hose 9, and the connected external piping system by again operating the hand pump 13. The operator monitors the pressure build-up by observing the pressure gauge 4. As soon as the intended test pressure is reached, the operator closes the first valve 12 and stops operating the hand pump 13. Because of the closed valves 12 and 13, the test fluid cannot flow from the pipeline 11 into the hand pump 13 or the relief line 15.

[0021] If the operator observes no pressure drop on the pressure gauge 4 over a specified period, particularly the prescribed holding time, a leak in the external piping system can be ruled out with a high degree of certainty. This section constitutes the actual pressure test. To reduce reading errors in this part of the test, the pressure gauge 4 can be equipped with a so-called drag pointer, which records the maximum pressure reached during the test and indicates any subsequent drop. In typical application scenarios, the operator will verify compliance with the holding time using a wristwatch or a timer.

[0022] After the pressure test is complete, the operator opens the second valve 14, thereby relieving the residual pressure in the pipeline 11, the pressure hose 9, and the connected external piping system. The connection between the pressure hose 9 and the external piping system can then be disconnected.

[0023] To simplify and accelerate the pressure test, the exemplary test pump 1 includes additional devices that support electronic recording of the pressure curve, logging of the recorded pressure data and other functions.

[0024] First, an electrical or electronic pressure sensor 18 is provided, which is connected to the pipeline 11 and to which the same static pressure is supplied that also controls the pressure indicator instrument 4.

[0025] The pressure sensor 18 is connected to an electronic data acquisition unit 20 via a data connection 19. This data connection 19 can be configured, for example, for the electrical transmission of analog or digitally coded signals. The data connection 19 allows the recurring or regular transfer of corresponding representations of the pressure values ​​from the pressure sensor 18 to the electronic data acquisition unit 20.

[0026] The exemplary representation of the electronic data acquisition unit 20 assumes an integrated power source, for example, a small battery or accumulator. A level switch 21 is shown separately from the electronic data acquisition unit 20 for the purpose of detecting the fill level of the measuring fluid in the reservoir 2. The level switch 21 is connected to the electronic data acquisition unit 20 via an exemplary electrical connection. The level switch 21 can be configured to interrupt the power supply to the electronic data acquisition unit 20 when the hydraulic test pump 1 is not in use, or to switch the electronic data acquisition unit 20 into an energy-saving operating mode.

[0027] The electronic data acquisition unit 20 can further comprise, as shown by way of example, a data interface 21 for data exchange with an external device 28. The data interface 21 can, in particular, be configured as a radio data interface 21, as is exemplified by the antenna symbol. The electronic data acquisition unit 20 can be configured to store the representations of the pressure measurement value taken from the pressure sensor 18 in time series and to transmit the stored time series to the external device 28 via the data interface 21.

[0028] Alternatively or additionally, the electronic data acquisition unit 20 can be configured to transmit the representations of the pressure measurement received from the pressure sensor 18 to the corresponding data interface 27 of an external device 28 without any technically avoidable time delay. In this case, the data acquisition unit 20 can, in particular, be configured to transmit the representations of the pressure measurement received from the pressure sensor 18 only if there is a change compared to the previously transmitted representations of the pressure measurement.

[0029] In the case of wireless data transmission via the so-called "Bluetooth Low Energy" (BLE) protocol, this corresponds to a so-called "notify" behavior of the electronic data acquisition unit 20 involved in the role of the server. The external device 27 can, for example, be a smartphone equipped with a screen display 29. In this case, the interpolated time series of the transmitted representations of the operator's pressure measurement can be displayed graphically.

[0030] The electronic data acquisition unit 20 can also be configured to support the operator in carrying out the pressure test by means of automated analyses and evaluations of the representations of the pressure measurement value received from the pressure sensor 18. Possible scenarios are briefly explained below.

[0031] In one embodiment, the electronic data acquisition unit 20 can be equipped with or connected to a short-term measurement device to assist the operator in applying the prescribed holding time during the pressure test. The automatic tracking of the holding time can be triggered either by the operator or automatically upon reaching the test pressure.

[0032] The operator can be notified when the dwell time has been reached by a signaling device connected to the electronic data acquisition unit 20. In the exemplary circuit, the signaling device is structurally integrated with the data acquisition unit 20 and is therefore not shown separately in the schematic diagram.

[0033] Alternatively or additionally, signaling can be achieved by transmitting appropriately representative data in accordance with Fig. 1 The corresponding data interface 27 of the external device 28 is used when the device is connected to or equipped with a suitable external signaling device 72. The exemplary smartphone 28 can, in particular, be controlled by means of wireless data transmission via the WiFi or BLE interface 27 to output a screen signal 29.

[0034] Alternatively, the electronic data acquisition unit 20 can, at the beginning of the holding time, control the external device 28 to output a signal delayed by the holding time. Particularly when the external device 28 is configured as a smartphone, its screen 29 can be controlled to display a countdown timer. The previously described functions for automatically monitoring the holding time can, in certain situations, allow an operator to perform another task while waiting for the holding time to expire. The automatic notification of the end of the holding time prevents unintentional exceeding of the required holding time. This can accelerate the execution of multiple pressure tests on various external piping systems or parts thereof, for example, in a branched building.

[0035] Alternatively or additionally, the electronic data acquisition unit 20 can be configured to signal a significant pressure drop that can be measured early, even before the end of the holding time. This can reduce the loss of productive time for the operator that would otherwise result from waiting until the holding time expires. The data acquisition unit can be configured to extrapolate the pressure drop measured in a short time interval to the entire holding time. This can be useful to the operator in certain situations when diagnosing the leak.

[0036] In a further alternative or additional configuration, the electronic data acquisition unit 20 can be set up to help the operator distinguish whether an observable pressure reduction is due to a thermal equalization process or is caused by a leak in the external piping system under investigation. In the first case, the test pressure would simply need to be increased by pumping to a value that remains safely above the test pressure after the adjustment is complete. In the second case, the pressure test could be terminated before the end of the holding time because the result is already known.

[0037] The Fig. 4 Figure 1 illustrates a first prototypical hydraulic situation in an external water supply system, which includes a section of an ideally water-filled pipeline 22. An ideal connection point 23 for the hydraulic test pump 1 is located on this pipeline 22.

[0038] A first deviation from ideal behavior, which may exist in a real water piping system, is in the Fig. 4 This is illustrated by two substitute symbols. On the right is the symbol of a constriction 24, which corresponds to a leak in a real, water-filled pipeline. On the left is the symbol of a pressure expansion vessel 25, which corresponds to an air bubble and / or structural elasticity in one or more parts of a real, water-filled water supply system.

[0039] The Fig. 5 illustrates a second prototypical hydraulic situation in an external piping system, which in turn includes a section of an ideally water-filled pipeline 22 and has an ideal connection point 23 for the hydraulic test pump 1.

[0040] Unlike the Fig. 4 are in the prototypical hydraulic situation of the Fig. 5 Two pressure equalization vessels 25, 26 are shown. The first pressure equalization vessel 25 on the left symbolizes, as in Fig. 4 an air bubble or structural elasticity in one or more parts of a real, water-filled water piping system.

[0041] The second expansion vessel 26 is shown on the right-hand side after the symbol for the constriction 32. The relationship between constriction 24 and the second expansion vessel 26 illustrates a slow, leak-free equalization process in a real water supply system. This slow, leak-free equalization process can involve pressure equalization via an accidentally partially closed shut-off valve or temperature equalization. In practice, temperature equalization can occur after a water supply system is filled with relatively warm or cold water. In such a case, temperature equalization will initially take place between the filled water and the material of the water supply system. A significantly slower equalization will simultaneously occur between the filled water supply system and the adjacent outdoor space or the adjacent building structure.For the sake of simplicity, however, multi-stage balancing processes will not be discussed here.

[0042] The practically relevant difference between the one caused by the Fig. 4 illustrated, first prototypical hydraulic situation and the one caused by the Fig. 5 The second, more prototypical hydraulic situation, as illustrated, apparently lies in the fact that in the first case there is a leak, but not in the second. Equally relevant for practical application is the finding that the hydraulic situations in the Fig. 4 und 5 Immediately after filling and applying a test pressure with a test pump via connection point 23, there is no difference. In both situations, the entire pressure drops at the constriction 24. Therefore, in both cases, the same quantity of test fluid flows from the pipeline 22 through the constriction 24. Thus, initially, the pressure in the pipeline will drop at the same rate in both situations.

[0043] Therefore, from an operator's perspective, observing a pressure drop using the connected test pump immediately after pressure build-up does not necessarily indicate the presence of a leak. Instead, the operator will assume this is due to compensatory processes and will monitor their progress until a clear asymptotic pattern emerges. Once the observed pressure has stabilized, the operator will compensate for the pressure loss by pumping additional air and then perform the actual pressure test.

[0044] In the Fig. 6 Exemplary pressure curves over time are shown in Figures 29 and 30 for both possibilities. In a leak-free equalization process, the observed pressure will typically settle on curve 29 at a point more or less far below the initial pressure. p 0 horizontal level p1. In the case of a leak, however, the pressure will asymptotically disappear completely and the reading of test pump 1 will accordingly tend to return to zero, as indicated by the lower curve 30.

[0045] Against this background, the data acquisition unit 20 can additionally or alternatively be configured to assist the operator in distinguishing between the two previously explained causes for a pressure drop observed at the beginning of the pressure test. In particular, the data acquisition unit 20 can be configured to estimate the best parameters for a parameterized mathematical model of a compensation process according to the representations of the pressure measurement value adopted by the pressure sensor 18.

[0046] In a basic embodiment, this can involve the decision of whether the obtained pressure measurements can be explained by a mathematical model of the situation in Fig. 4 or through a mathematical model of the situation in Fig. 5 can be approximated more accurately.

[0047] In particular, a closed-form expression can be used to approximate the time dependence of pressure in the models of Fig. 4 und 5 apparently through the formula p ( t ) = p 0 · e -βt< according to curve 31 in Fig. 6 or by the formula p' ( t ) = p ∞ + ( p 0 - p 0∞ ) · e -βt< specified according to curve 31 in Fig. 6 In the formulas, this denotes... p 0 the initial pressure at the beginning of the exam and p ∞ is the asymptotic final pressure, which the model approaches more and more closely over time. The model parameter β is the inverse of the time interval after which the difference between the approximate pressure p ( t ) and the zero level or the valuep ∞ on the 1 e has reduced the fraction, which corresponds to a decrease of approximately 73%.

[0048] A simple algorithm, executed in the data acquisition unit 20, can be set up to make a best-fit estimate of the parameters in both models for any set of pressure measurements and, with an increasing number of available time-based pressure measurements, to select the model that shows the best fit in terms of computational deviation evaluation.

[0049] If the algorithm decides that the approximation should match the model p ( t ) the Fig. 4 If the system can be better adapted to the increasing number of pressure measurements over time, this indicates a leak. In this case, the algorithm can be configured to signal to the operator via a signaling device that a leak has occurred. This eliminates the need for the operator to wait any longer.

[0050] If the algorithm decides that the approximation p' ( t ) according to the model of Fig. 5 The fact that the system can be better adapted to the increasing number of pressure measurements over time suggests an internal compensation process. In this case, the algorithm can be configured to signal to the operator via a signaling device that a successful pressure test is still possible after the test pressure has been restored.

[0051] Fig. 3 Finally, it shows an alternative hydraulic circuit diagram for the 'X' section in Fig. 2 , which illustrates a possible modification of the previously described hydraulic test pump 1. Instead of the valve 12, which is operated via a rotary handle in Fig. 2 Alternatively, a self-operating check valve 32 is provided. The self-operating nature of the check valve 32 eliminates the need for a rotary handle, which may make operation more intuitive.

[0052] Since operator-controlled relief of line 11 is not possible via the check valve 32, the manually operated valve 6 leading to the relief line 15 must branch off downstream in the pump's delivery direction behind the check valve 31. This effectively includes an inherent pressure test of the tightness of two hydraulic shut-off elements 12 and 32. In the design according to Fig. 2 However, only the tightness of valve 12 will influence the result of the pressure test. From this perspective, the setup could be configured according to the hydraulic circuit diagram of the... Fig. 2 to be considered more technically robust.

Claims

1. Hydraulic test pump (1) having a container (2) for a test liquid, a connection device (10) for connection to an external line system, a mechanical pressure-indicating instrument (4) hydraulically connected to the connection device (10), a manually operated piston pump (13) connectable to the connection device for conveying a test liquid from the container (2) to an external line system connected to the connection device (10), an electrical pressure sensor (18) arranged in hydraulic connection with the mechanical pressure-indicating instrument (4), an electronic data acquisition unit (20), which is connected to the electrical pressure sensor (18) via a data connection (19), the data connection (19) being configured for the temporally recurring or regular transfer of corresponding representations of the pressure values from the pressure sensor (18) to the electronic data acquisition unit (20), and an electrical energy source power-connectable to the electronic data acquisition unit (20), characterized in that the power connection is established and / or interrupted by a level switch depending on the fill level in the container (2).

2. Hydraulic test pump (1) according to Claim 1, wherein the electronic data acquisition unit (20) is equipped with a device for short-term measurement in order to assist an operator in applying the prescribed holding time during the pressure test.

3. Hydraulic test pump (1) according to Claim 2, further having a signalling device which is configured to inform an operator that the prescribed holding time during the pressure test has elapsed.

4. Hydraulic test pump (1) according to any of Claims 1 to 3, further having a data interface (21), wherein the data interface (21) is connected to the data acquisition unit (20) in order to allow data exchange between the data acquisition unit (20) and an external device (28), and wherein the data interface (21) is, in particular, a radio data interface.

5. Hydraulic test pump (1) according to any of Claims 1 to 4, wherein the electronic data acquisition unit (20) comprises a decision device which, in the case of a pressure reduction detectable in the representations of the pressure values from the pressure sensor (18), calculates a plausibility value which can be interpreted as an assessment of whether the pressure reduction is due either to a compensation process without loss of test liquid or to a leak with loss of test liquid.

6. Hydraulic test pump (1) according to Claim 5, wherein the decision device is configured to optimize model parameters in a plurality of mathematical models for hydrodynamic situations.

7. Hydraulic test pump (1) according to any of the preceding claims, wherein the container (2) is a cuboidal basin (2) which is partially covered from above by an instrument panel (3), and wherein, in particular, the manually operated piston pump (13) is arranged in an aperture in the instrument panel (3).

8. Hydraulic test pump (1) according to any of the preceding claims, wherein the connection device (10) is arranged at the protruding end of a flexible pressure hose (9) hydraulically connected to the mechanical pressure-indicating instrument (4).

Images