Question 1

What is the ideal location for installing silencers?

Accepted Answer

When installing a vent silencer, the following basic guidelines should be followed:

To achieve optimal noise reduction and ensure long-term operational safety, vent silencers should be installed at a high location, well away from regularly occupied work areas.

Avoid placing the silencer close to façades to minimize sound reflections and prevent potential structural damage.

Note:
 Vented hot steam in particular can cause serious damage to nearby structures. Reflected sound waves from walls can also increase sound pressure levels by up to 10 dB. If the specific installation conditions require placement near a wall, it is strongly recommended to use a properly aligned goose neck accessory to direct the exhaust flow away from nearby surfaces.
A rooftop is typically an excellent location for installing vent silencers.

Question 2

How can GLAUNACH Vent Silencers be installed?

Accepted Answer

Glaunach silencers are often designed to be so lightweight and compact that, in many cases, they can be supported directly by the blow-off pipe without the need for additional mounting structures. For other installation scenarios, Glaunach offers a wide range of mounting options to ensure flexible and secure installation. Depending on the structural and technical requirements, the following installation types are commonly used:

1. Roof-Independent Installation
 The silencer is mounted to the blow-off pipe, which is structurally supported independently of the roof. This setup places no load on the roof structure, and the only roof modification required is the installation of a suitable roof seal. Thermal expansion of the pipe is accommodated by allowing relative movement of the silencer to the roof—ideally with a sliding seal.

2. In-Roof Installation
 In this setup, the blow-off pipe is fixed to the underside of the roof structure (e.g., steel beams), with only the top section of the silencer extending above the roof. This design minimizes wind loads and reduces the impact of thermal expansion at the roof penetration point.

3. On-Roof Installation
The silencer is mounted directly on the roof using support brackets. This method is especially suitable for larger silencers, particularly when installed on a construction scaffold or structural platform above the roof level.

4. Inline Installation
In this configuration, the silencer is integrated directly into the piping system and becomes a part of the pipeline itself. This method is commonly used in closed-loop systems or in situations where there is no space available on the roof for an external silencer.

Note:
The optimal installation method depends on the specific operating conditions and site constraints. Glaunach is happy to provide tailored recommendations for your particular application.

Question 3

What should be considered when designing the piping for a vent silencer?

Accepted Answer

To ensure effective noise reduction and safe operation, the following aspects should be considered when designing the blow-off piping:

The blow-off pipe leading to the silencer should be designed to keep the gas velocity below Mach 0.2 in order to minimize flow noise.

The pipe should be as straight as possible and maintain a consistent diameter to avoid noise caused by turbulent flow conditions.

If this ideal setup cannot be fully achieved, all exposed sections of the piping must be acoustically insulated. Otherwise, noise radiated from the piping or valves may exceed the residual noise from the silencer and significantly reduce its overall effectiveness.

In general, higher pressures upstream of the silencer are advantageous, as they reduce the volumetric flow rate and allow for a more compact and cost-efficient silencer design.

Rule of Thumb:
Higher inlet pressure = smaller pipe diameter = smaller and more economical silencer

Question 4

What should be considered when draining rainwater and condensate from a silencer?

Accepted Answer

Each Glaunach silencer is equipped with a drainage outlet at the bottom of the silencer shell. This allows for the controlled discharge of rainwater and condensate.

The dewatering pipe can either remain open - allowing water to drain freely over the roof - or be connected to a suitable drainage system, such as a steam condensate line.

⚠️Caution:

The discharged condensate may be hot. In such cases, it is recommended to either connect the outlet to a proper drainage system or place a drip plate or collection cup beneath the outlet to prevent long-term damage to the roof structure.

Never route the drain line into the blow-off line. This significantly reduces noise attenuation and can cause severe damage to the silencer.

In cold environments, special attention must be given to the risk of freezing. If the drainage pipe freezes, water buildup can occur inside the silencer, potentially leading to severe damage. Adequate insulation or heat tracing may be required to prevent this.

Question 5

What should be considered during the initial commissioning of a GLAUNACH silencer?

Accepted Answer

Several preparatory steps are required before the initial commissioning of a silencer to ensure safe and trouble-free operation:

1. Preparation of the blow-off line
 Before installing the silencer, the blow-off line must be thoroughly cleaned and blown through for the first time without the silencer installed. Otherwise, contaminants (e.g. rust particles, installation debris, etc.) from the pressurized system could clog or damage the silencer.

2. Removal of transport safety devices
 Before the first blow-off operation, all protective covers and transport brackets on the silencer must be completely removed.

3. Commissioning of "Sliding Diffuser" silencers
 Sliding diffuser silencers are delivered with three bolts securing them in their transport position. These bolts must be removed after installation to enable the diffuser to operate correctly.
 After the first blow-off, the stuffing box should be checked and, if necessary, retightened to ensure long-term sealing.

4. Personnel training and qualification
 All personnel responsible for commissioning must have fully read and understood the corresponding operating manual and all relevant safety instructions. If these documents have not already been provided, they are available online.
 Additionally, it must be ensured that the personnel involved are appropriately trained and qualified to perform the installation, commissioning, and inspection of the silencer.

Note:
For the initial commissioning of systems – during the so-called blow-out process – Glaunach provides a range of rental silencers that are returned and refurbished after use. This ensures that the system is handed over free of installation debris.

Question 6

Can a silencer be installed directly next to a building facade?

Accepted Answer

In general, a steam outlet should be placed at a safe distance from building façades. In practice, a minimum distance of 2 to 3 meters ( 6 to 10 ft) is recommended unless appropriate protective measures are in place. A specific evaluation must be carried out as part of a risk assessment.

If installing a silencer directly adjacent to a building wall cannot be avoided, this is only acceptable under certain conditions:

The steam must not pose any risk to people, windows, or façade components.
The steam should preferably be discharged away from the building façade, for example by using a deflector or suitable discharge pipe.
Proper protective elements such as deflector plates, thermal shielding, or barriers must be included.
Backflow of hot steam or condensate toward the façade must be prevented.
A thermal and acoustic assessment by qualified personnel is recommended.

The installation company is fully responsible for proper and safe implementation. Written documentation within the risk assessment process is strongly advised.

When planning steam outlets or silencers near building façades, the acoustic directivity of the outlet must be carefully taken into account.

The goal is to avoid sound reflections on the facade and to prevent unintended noise emission into sensitive areas (such as offices, break rooms, or neighboring properties).

By orienting the outlet appropriately and using suitable discharge components, sound emissions can be significantly reduced and directed toward less critical zones.

Outlet to safely redirect exhaust gas flow away from the building:

Question 7

Why does the stainless-steel noise absorber develop visible bulges?

Accepted Answer

The perforated stainless steel cylinder of the absorber is designed to accommodate thermal expansion during operation. As a result, it may form smooth, large-scale waves. This deformation represents a stable post-buckling response of the thin-walled shell, allowing thermal expansion to be accommodated while reducing thermally induced restraint stresses and the resulting loads transferred to the welded joints.Depending on the manufacturing conditions and the temperature during fabrication, transportation, or installation, this waviness may already be visible upon delivery. During operation, the degree of waviness may vary with temperature.This deformation is cosmetic only and does not affect the intended function or performance of the equipment. Under the specified operating conditions, it is not expected to affect the structural integrity or service life of the equipment.Stable post-buckling is a well-established and widely recognized behavior of thin-walled shell structures subjected to thermal or compressive loading.

Frequently asked questions