Marsh Funnel Viscosity Test

Marsh Funnel Viscosity Test
(API RP 13B-1 — Drilling Fluid Viscosity)

Measurement of the apparent viscosity of drilling mud (bentonite slurry) and stabilising fluids using the Marsh funnel — a rapid field and laboratory quality control test for bored pile and diaphragm wall construction.

Overview

What is the Marsh Funnel Viscosity Test?

The Marsh Funnel Viscosity test measures the flow time of 946ml of drilling fluid through a standard Marsh funnel — a simple cone-shaped funnel with a defined orifice (4.76mm dia). The result is expressed in seconds (Marsh funnel seconds). Fresh water gives 26±0.5 seconds at 21°C; bentonite slurry used in bored pile construction typically targets 30–90 seconds depending on soil conditions.

Conducted as per API RP 13B-1, Marsh funnel viscosity is the standard on-site quality check for stabilising bentonite slurry used in bored pile and diaphragm wall excavations. It is specified in IS 2911 Part 4 and EFFC/DFI guidelines for drilling fluid monitoring. Global Lab tests Marsh funnel viscosity on bentonite slurry samples submitted from construction sites.

API RP 13B-1 Standard

Calibrated Marsh funnel and graduated cup per API standard procedure.

IS 2911 Pile Construction

Bentonite slurry viscosity monitoring per IS 2911 Part 4 bored pile requirements.

Rapid 24-Hour Test

Quickest drilling fluid test — result available same day or within 24 hours.

Bored Pile & Diaphragm Wall

Essential QC test during drilling fluid stabilised pile and diaphragm wall construction.

NABL Certified Reports

All test and calibration results are backed by traceable measurements and standardized procedures.

Multiple Sample Testing

Serial testing at different depths or at different times during construction.

Test in Action

Marsh Funnel Viscosity Test — Site Images

Marsh Funnel with Graduated Cup — 946ml Efflux Test

Bentonite Slurry Sample from Bored Pile Excavation

Efflux Time in Seconds — IS 2911 Compliance Check

Test Procedure

How the Marsh Funnel Viscosity Test is Conducted

1

Funnel Calibration Check

Marsh funnel checked — 946ml of fresh water at 21°C should efflux in 26±0.5 seconds.
2

Sample Collection

Bentonite slurry sample collected from boring at the required depth or stage of construction.
3

Temperature Measurement

Slurry temperature measured — result reported at actual temperature per API RP 13B-1.
4

Marsh Funnel Test

Finger placed over orifice. 946ml slurry poured through screen into funnel. Finger removed. Time for 946ml to flow out into graduated cup recorded.
5

Result & Report

Marsh funnel viscosity reported in seconds at measured temperature. Comparison to project specification (typically 30–90 sec). NABL report within 24 hours.

Standards & Specifications

Applicable Test Standards

Standard	Title	Scope	Type
API RP 13B-1	Recommended Practice for Field Testing Water-Based Drilling Fluids	Marsh Funnel Viscosity	API
IS 2911 Part 4	Code of Practice for Design and Construction of Pile Foundations — Load Tests	Bored Pile Drilling	Indian Standard
EFFC/DFI Guidelines	Guide to Good Practice for the Use of Drilling Fluids	Drilling Fluid QC	EFFC/DFI
IS 6403	Code of Practice for Determination of Bearing Capacity of Shallow Foundations	Geotechnical Reference	Indian Standard

Applications

Where is the Marsh Funnel Viscosity Test Used?

Bored pile bentonite slurry quality control during rotary boring

Diaphragm wall panel excavation stabilising fluid monitoring

CFA pile boring fluid viscosity check before and after boring

Large diameter bored pile under slurry conditions — IS 2911 compliance

River bed drilling where artesian pressure requires dense bentonite slurry

Geotechnical investigation boreholes requiring slurry stabilisation in weak soils

Why Choose Global Lab

Our Advantages

NABL Accredited ReportsLegally valid API RP 13B-1 viscosity certificates for pile construction records.

IS 2911 ComplianceResults referenced against IS 2911 Part 4 bentonite slurry quality requirements.

Same-Day ResultsMarsh funnel test completed and result available same day.

Construction Phase SupportTesting available 6 days a week to support continuous piling operations.

Pan-India CoverageTesting at all 7 NABL-accredited locations.

Combined Bentonite PackageMarsh funnel + pH + density + sand content offered as a complete bentonite QC package.

Marsh Funnel Viscosity Test(API RP 13B-1 — Drilling Fluid Viscosity)