Livingston & Haven

The versions of the HYDAC safety and locking block SAF, its special versions and the DSV10 as a simple variant of the SAF10, are practical hydraulic accessories for blocking and relieving hydraulic accumulators or consumers. They are in compliance with safety regulations in accordance with DGRL9723EG, DIN EN 982, EN 14359 and the regulations of the Ordinance on Industrial Safety and Health [Betriebssicherheitsverordung (BetrSichV)]. The optimum combination of the safety and shut-off blocks considerably simplifies the connection between the consumer and the hydraulic system and offer the following exemplary advantages: Minimum of space and maintenance, Minimum of installation required (1 SAF replaces as a rule up to 10 individual pipe connections), considerable reduction of installation time, adapters for various accumulator types and additional valves (pilot-operated check valves, flow control valves, etc).

​Piston Accumulators are a cost effective option for numerous functions involving energy storage, and sometimes shock absorption in a hydraulic or fluid system. They are well suited for applications needing: High Pressure Ratios Large Volumes of Oil High Fluid flow rates Volumes monitoring by way of piston position sensor or switch systems ​Advantages of Using the Low-friction Sealing System (type 2): Minimum friction Suitable for low pressure differentials No start-up friction, no stick-slip Low noise, no vibration High piston speeds up to 12 ftsec continuous Improved accumulator efficiency High life expectancy, low maintance requirements Construction HYDAC piston accumulators consist of: A cylinder with a finely finished internal surface An end cap on the gas side and fluid side, sealed with 0-rings A lightweight metal piston A variety of sealing systems are available depending on the application Sealing Systems Precise information about the proposed operating conditions is required in order to select the most appropriate sealing system. Important criteria for this selection are: Number of actuations or cycles Piston speed Temperature fluctuation Operating fluid Cleaniness of fluid Maintenance requirements Seal Materials The following sealing elastomers are available, depending on the operating conditions: NBR (acrylic nitrile butadiene rubber) FPM (fluoro-elastomer) PUR (polyurethane) Suitable materials are also available for low temperature applications. Fluids The following sealing materials are suitable for the fluids listed below: NBR, resistant to: Mineral Oils (HL and HLP) Non-flammable fluids from groups HFA, HFB, and HFC Water and seawater up to approx. 100°C NBR, not resistant to Aromatic hydrocarbons Chlorinated hydrocarbons Amines and ketones Hydraulic fluids from the HFD Groups FPM, resistant to: Mineral Oils (HL and HLP) Hydraulic fluids from the HFD Groups Fuels as well as aromatic and chlorinated hydrocarbons Inorganic acids (but not all, please contact HYDAC) System Mounting HYDAC piston accumulators may operate in any position. Vertical installation is preferable with the gas side up. We recommend the use of our mounting components, which are detailed on page 84, to minimize risk of failure due to system vibrations. Effects of Seal Friction The permissible piston velocity depends on the sealing friction. Higher piston velocities are possible where there is less sealing friction. HYDAC piston accumulators with low friction piston seals allow continuous operating velocities of up to 12 ftsec with short bursts, up to 15 ftsec (see type 2 piston). Small pressure differentials between gas and oil side improve the effectiveness of HYDAC piston accumulators. To emphasize the friction effect on the pressure curve during an accumulation cycle, measurements with various sealing systems are illustrated. The measurements graphs below are a true representation of the gas and oil pressure of piston accumulators with different sealing systems. The comparison of these two measurements clearly shows the difference int he pressure differential between gas and oil side: Graph 1: Δp max. ~ 125 psi Graph 2: Δp max. ~ 14.5 psi The effect of the sealing friction on the working pressure is particularly striking in traditional piston designs. Abrupt piston movements (the stick-slip effect) are caused by the seal friction as shown in Graph 1. the low sealing friction of HYDAC type 2 pistons drastically reduces the stick-slip effect therefore maximizing piston responsiveness.

To maintain system performance HYDAC recommends that the gas precharge pressure is checked regularly. The inevitable loss of gas precharge pressure due to permeability will change the system effectiveness (performance) and could cause damage to the bladder, diaphragm, or piston accumulator. HYDAC charging and gauging units allow hydro-pneumatic accumulators to be precharged with dry nitrogen. For these purposes, a charging and gauging unit is connected to a commercially available nitrogen bottle via a flexible charging hose. All HYDAC charging and gauging units incorporate a gauge and check valve in the charging connection, and a manual bleed valve with a T-handle. HYDAC offers two types of charging and gauging units: FPK for use with HYDAC version 1 gas valve FPS for use with HYDAC version 4 gas valve​

​Pulsations and shocks in hydraulics lines can result in costly damage to the piping and other system components. Reciprocating piston pumps by design create pressure pulsations, vibrations, and noise in the systems. HYDAC suction stabilizers, pulsations can make control in servo systems nearly impossible without installing a pulsation damperner. HYDAC shock absorbers can be applied to greatly reduce shock wave energy. These waves can be harmful to all components in your hydraulic system. Shock waves can be created by closing a valve in a high flow line, such as one found in a petroleum terminal.

The WDV3 Electrical Drain is designed to remove condensate from compressors, compressed air dryers and receivers up to any size, type or manufacturer. The WDV3 offers true installation simplicity and it is recognized as the most reliable and best performing condensate drain worldwide. The large orifice in the direct acting valve, combined with its sophisticated timer module ensure many years of trouble-free draining of condensate. Benefits Does Not Air-Lock During Operation. Compressed Air Systems Up to Any Size. Also Available In Stainless Steel. The Direct Acting Valve Is Serviceable. Suitable for All Types of Compressors. TEST (Micro-Switch) Feature. High Time Cycle Accuracy. Large (4.5mm) Valve Orifice.

Diaphragm type accumulators are used for energy storage, shock and vibration absorption and leakage oil or volume compensation in hydraulic systems. They consist of a pressure-resistant tank (high-tensile steel) whose interior is split into a gas and a fluid side by an elastic diaphragm. When the operating pressure is increased, hydraulic fluid flows into the accumulator and compresses the gas until the gas pressure is identical to the fluid pressure. When the operating pressure is reduced, the gas expands again and, in this way, feeds the hydraulic system with hydraulic fluid. Nominal volume 0.075 to 3.5 liters Component series 1X and 2X Maximum operating pressure 350 bar Hydraulic accumulator as per Pressure Equipment Directive 9723EC Diaphragm material for different applications Use e.g. as energy storage in intermittent operation systems, energy reserve for emergencies, compensation of leakage losses, shock and vibration absorption